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MODELING COUPLED FLUID FLOW AND GEOMECHANICAL AND GEOPHYSICAL PHENOMENA WITHIN A FINITE ELEMENT for the modeling of geomechanical effects induced by reservoir production/injection and the cyclic dependence
Can We Accurately Model Fluid Flow in Shale?
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
2013 00:00 Over 20 trillion cubic meters of natural gas are trapped in shale, but many shale oil and gas producers still use models of underground fluid flow that date back to...
FLUID FLOW MODELING OF RESIN TRANSFER MOLDING FOR COMPOSITE MATERIAL WIND TURBINE BLADE STRUCTURES.............................................................................................................7 Composite Materials...................................................................................................7 Material Properties
Notes 10. A thermohydrodynamic bulk-flow model for fluid film bearings
San Andres, Luis
Notes 10. THERMOHYDRODYNAMIC BULK-FLOW MODEL IN THIN FILM LUBRICATION ? Dr. Luis San Andr?s (2009) 1 Notes 10. Thermohydrodynamic Bulk-Flow Model in Thin Film Lubrication General flow characteristics in oil lubricated fluid film... regimes Notes 10. THERMOHYDRODYNAMIC BULK-FLOW MODEL IN THIN FILM LUBRICATION ? Dr. Luis San Andr?s (2009) 2 Bulk-Flow Equations for Thin Fluid Films The fluid flow within a thin film region, see Fig.1, is governed by the continuity...
Fluid flow and heat transfer modeling for castings
Domanus, H.M.; Liu, Y.Y.; Sha, W.T.
Casting is fundamental to manufacturing of many types of equipment and products. Although casting is a very old technology that has been in existence for hundreds of years, it remains a highly empirical technology, and production of new castings requires an expensive and time-consuming trial-and-error approach. In recent years, mathematical modeling of casting has received increasing attention; however, a majority of the modeling work has been in the area of heat transfer and solidification. Very little work has been done in modeling fluid flow of the liquid melt. This paper presents a model of fluid flow coupled with heat transfer of a liquid melt for casting processes. The model to be described in this paper is an extension of the COMMIX code and is capable of handling castings with any shape, size, and material. A feature of this model is the ability to track the liquid/gas interface and liquid/solid interface. The flow of liquid melt through the sprue and runners and into the mold cavity is calculated as well as three-dimensional temperature and velocity distributions of the liquid melt throughout the casting process. 14 refs., 13 figs.
A Mixed Finite Element Framework for Modeling Coupled Fluid Flow ...
Birendra Jha
and in enhanced oil recovery techniques such as steam assisted gravity ..... When fluid flows through a porous medium there are three forces acting, per unit.
Monitoring and Modeling Fluid Flow in a Developing EGS Reservoir...
Broader source: Energy.gov (indexed) [DOE]
model fluid injection into a tight reservoir on the edges of a hydrothermal field. Use seismic data to constrain geomechanicalhydrologicthermal model of reservoir....
Monitoring and Modeling Fluid Flow in a Developing Enhanced Geothermal...
Broader source: Energy.gov (indexed) [DOE]
fluid injection into a tight reservoir on the edges of a hydrothermal field; to use seismic data to constrain geomechanicalhydrologicthermal model of reservoir; to model for...
Monitoring and Modeling Fluid Flow in a Developing EGS Reservoir
Broader source: Energy.gov (indexed) [DOE]
fluid injection into a tight reservoir on the edges of a hydrothermal field * Use seismic data to constrain geomechanicalhydrologicthermal model of reservoir * Model for...
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow
Boyer, Edmond
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S modeling of the turbulent flow in a rotor-stator cavity subjected to a superimposed throughflow with heat the dynamical effects from the heat transfer process. The fluid flow in an enclosed disk system with axial
Monitoring and Modeling Fluid Flow in a Developing EGS Reservoir
Broader source: Energy.gov [DOE]
Project objectives: Better understand and model fluid injection into a tight reservoir on the edges of a hydrothermal field. Use seismic data to constrain geomechanical/hydrologic/thermal model of reservoir.
Coupled fluid flow and geomechanical deformation modeling Susan E. Minkoff a,*, C. Mike Stoneb,1
Minkoff, Susan E.
Coupled fluid flow and geomechanical deformation modeling Susan E. Minkoff a,*, C. Mike Stoneb,1 reservoir properties. Pore pressures from flow are used as loads for the geomechanics code
Network model of fluid flow in semi-solid aluminum alloys W.O. Dijkstra a
Vuik, Kees
Network model of fluid flow in semi-solid aluminum alloys W.O. Dijkstra a , C. Vuik b , L within a semi-solid aluminum alloy. The model consists of a set of connected channels representing; Fluid flow; Aluminum alloys; Permeability; Macrosegregation 1. Introduction Early simulations
Multiscale Modeling and Simulation of Fluid Flows in Inelastic Media
Popov, Peter
in porous media (e.g. soil), Elasticity equations in heterogeneous media (concrete, asphalt), etc porous media s The Fluid-Structure interaction (FSI) problem at the microscale and numerical methods with computational solutions s Numerical upscaling of flow in deformable porous media #12;- p. 3/42 Why homogenize
TOPAZ: a computer code for modeling heat transfer and fluid flow in arbitrary networks of pipes, flow branches, and vessels
Winters, W.S.
An overview of the computer code TOPAZ (Transient-One-Dimensional Pipe Flow Analyzer) is presented. TOPAZ models the flow of compressible and incompressible fluids through complex and arbitrary arrangements of pipes, valves, flow branches and vessels. Heat transfer to and from the fluid containment structures (i.e. vessel and pipe walls) can also be modeled. This document includes discussions of the fluid flow equations and containment heat conduction equations. The modeling philosophy, numerical integration technique, code architecture, and methods for generating the computational mesh are also discussed.
Modeling Fluid Flow in Natural Systems, Model Validation and...
media is another important process. The observed relationship between water flux and hydraulic gradient can be highly non-linear. To capture this non-Darcian flow behavior, a new...
A Preliminary Study to Assess Model Uncertainties in Fluid Flows
Delchini, Marc Olivier
of the fluid. ? The sound speed, c, is assumed to be constant even if it usually depends on the temperature and the pressure. This is a good approximation for liquids but not for gases. The sound speed is reactor-dependent. ? The Equation Of State (EOS... to the temperature. This parameter is assumed constant in this model. 7 ? ???P is the dilatation of the density due to the pressure. This parameter is also assumed constant but is different for different sound speeds. Its expression is as follows: ?? ?P = 1...
Numerical models of caldera deformation: Effects of multiphase and multicomponent hydrothermal fluid flow
Numerical models of caldera deformation: Effects of multiphase and multicomponent hydrothermal studies addressing the effects of multiphase flow on crustal mechanics have been attempted. Recent numerical simulations of multiphase (liquid-gas), multicomponent (H2OCO2) hydrothermal fluid flow
Computational Fluid Dynamics Modeling of a Lithium/Thionyl Chloride Battery with Electrolyte Flow
Wang, Chao-Yang
Computational Fluid Dynamics Modeling of a Lithium/Thionyl Chloride Battery with Electrolyte Flow W-dimensional model is developed to simulate discharge of a primary lithium/thionyl chloride battery. The model to the first task with important examples of lead-acid,1-3 nickel-metal hydride,4-8 and lithium-based batteries
Mathematical Modeling and Simulation for Applications of Fluid Flow in Porous Media \\Lambda
Ewing, Richard E.
Mathematical Modeling and Simulation for Applications of Fluid Flow in Porous Media \\Lambda Richard descriptions at various length scales, modeling the effects of this heterogeneity of the porous medium a computer code has been developed which gives concrete quantitative results for the total model, this out
Notes 10. A thermohydrodynamic bulk-flow model for fluid film bearings�
San Andres, Luis
The complete set of bulk-flow equations for the analysis of turbulent flow fluid film bearings. Importance of thermal effects in process fluid applications. A CFD method for solution of the bulk-flow equations....
Fully coupled thermal-mechanical-fluid flow model for nonliner geologic systems
Hart, R.D.
A single model is presented which describes fully coupled thermal-mechanical-fluid flow behavior of highly nonlinear, dynamic or quasistatic, porous geologic systems. The mathematical formulation for the model utilizes the continuum theory of mixtures to describe the multiphase nature of the system, and incremental linear constitutive theory to describe the path dependency of nonlinear material behavior. The model, incorporated in an explicit finite difference numerical procedure, was implemented in two different computer codes. A special-purpose one-dimensional code, SNEAKY, was written for initial validation of the coupling mechanisms and testing of the coupled model logic. A general purpose commercially available code, STEALTH, developed for modeling dynamic nonlinear thermomechanical processes, was modified to include fluid flow behavior and the coupling constitutive model. The fully explicit approach in the coupled calculation facilitated the inclusion of the coupling mechanisms and complex constitutive behavior. Analytical solutions pertaining to consolidation theory for soils, thermoelasticity for solids, and hydrothermal convection theory provided verification of stress and fluid flow, stress and conductive heat transfer, and heat transfer and fluid flow couplings, respectively, in the coupled model. A limited validation of the adequacy of the coupling constitutive assumptions was also performed by comparison with the physical response from two laboratory tests. Finally, the full potential of the coupled model is illustrated for geotechnical applications in energy-resource related areas. Examples in the areas of nuclear waste isolation and cut-and-fill mining are cited.
Fluid-particle flow modelling and validation using two-way-coupled mesoscale SPH-DEM
Robinson, Martin; Ramaioli, Marco
We present a meshless simulation method for multiphase fluid-particle flows coupling Smoothed Particle Hydrodynamics (SPH) and the Discrete Element Method (DEM). Rather than fully resolving the interstitial fluid, which is often infeasible, the unresolved fluid model is based on the locally averaged Navier Stokes equations, which are coupled with a DEM model for the solid phase. In contrast to similar mesh-based Discrete Particle Methods (DPMs), this is a purely particle-based method and enjoys the flexibility that comes from the lack of a prescribed mesh. It is suitable for problems such as free surface flow or flow around complex, moving and/or intermeshed geometries. It can be used for both one and two-way coupling and is applicable to both dilute and dense particle flows. A comprehensive validation procedure for fluid-particle simulations is presented and applied to the SPH-DEM method, using simulations of single and multiple particle sedimentation in a 3D fluid column and comparison with analytical model...
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow
Boyer, Edmond
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S in a rotor-stator cavity subjected to a superimposed throughflow with heat transfer. Nu- merical predictions field from the heat transfer process. The turbulent flux is approximated by a gradient hypothesis
CIRQ: Qualitative fluid flow modelling for aerospace FMEA applications Neal Snooke
Snooke, Neal
M2 CIRQ: Qualitative fluid flow modelling for aerospace FMEA applications Neal Snooke Department- oped on top of the MCIRQ simulator with the aim to produce an automated FMEA for aircraft fuel systems similar to pre- viously developed automated electrical FMEA. Introduction This paper describes a circuit
Ewing, Richard E.
of environmental effects of air polution is extensive. Here we address the need for using similar models
Visualizing multiphase flow and trapped fluid configurations in a model three-dimensional porous medium
Amber T. Krummel; Sujit S. Datta; Stefan M�nster; David A. Weitz
We report an approach to fully visualize the flow of two immiscible fluids through a model three-dimensional (3D) porous medium at pore-scale resolution. Using confocal microscopy, we directly image the drainage of the medium by the non-wetting oil and subsequent imbibition by the wetting fluid. During imbibition, the wetting fluid pinches off threads of oil in the narrow crevices of the medium, forming disconnected oil ganglia. Some of these ganglia remain trapped within the medium. By resolving the full 3D structure of the trapped ganglia, we show that the typical ganglion size, and the total amount of residual oil, decreases as the capillary number Ca increases; this behavior reflects the competition between the viscous pressure in the wetting fluid and the capillary pressure required to force oil through the pores of the medium. This work thus shows how pore-scale fluid dynamics influence the trapped fluid configurations in multiphase flow through 3D porous media.
Magnetically stimulated fluid flow patterns
Martin, Jim; Solis, Kyle
Sandia National Laboratories' Jim Martin and Kyle Solis explain research on the effects of magnetic fields on fluid flows and how they stimulate vigorous flows. Fluid flow is a necessary phenomenon in everything from reactors to cooling engines in cars.
Magnetically stimulated fluid flow patterns
Martin, Jim; Solis, Kyle
Sandia National Laboratories' Jim Martin and Kyle Solis explain research on the effects of magnetic fields on fluid flows and how they stimulate vigorous flows. Fluid flow is a necessary phenomenon in everything from reactors to cooling engines in cars.
Hossain, M. Enamul
thickness, rock and fluid properties independent of pressure and laminar flow are reported in many the rock and fluid properties to be constant in time. It is very important to consider the variation to consider the time variation of fluid and rock properties in a proper way. Therefore, Darcys law should
Analysis Of Residence Time Distribution Of Fluid Flow By Axial Dispersion Model
Sugiharto [Department of Physics, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Jl. Ganesha 10, Bandung 40132 (Indonesia); Centre for Applications of Isotopes and Radiation Technology-National Nuclear Energy Agency, Jl. Lebak Bulus Raya No. 49, Jakarta 12440 (Indonesia); Su'ud, Zaki; Kurniadi, Rizal; Waris, Abdul [Centre for Applications of Isotopes and Radiation Technology-National Nuclear Energy Agency, Jl. Lebak Bulus Raya No. 49, Jakarta 12440 (Indonesia); Abidin, Zainal [Department of Physics, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Jl. Ganesha 10, Bandung 40132 (Indonesia)
Radioactive tracer {sup 82}Br in the form of KBr-82 with activity {+-} 1 mCi has been injected into steel pipeline to qualify the extent dispersion of water flowing inside it. Internal diameter of the pipe is 3 in. The water source was originated from water tank through which the water flow gravitically into the pipeline. Two collimated sodium iodide detectors were used in this experiment each of which was placed on the top of the pipeline at the distance of 8 and 11 m from injection point respectively. Residence time distribution (RTD) curves obtained from injection of tracer are elaborated numerically to find information of the fluid flow properties. The transit time of tracer calculated from the mean residence time (MRT) of each RTD curves is 14.9 s, therefore the flow velocity of the water is 0.2 m/s. The dispersion number, D/uL, for each RTD curve estimated by using axial dispersion model are 0.055 and 0.06 respectively. These calculations are performed after fitting the simulated axial dispersion model on the experiment curves. These results indicated that the extent of dispersion of water flowing in the pipeline is in the category of intermediate.
Parameter estimation from flowing fluid temperature logging data in unsaturated fractured rock using multiphase inverse modeling
Mukhopadhyay, S.; Tsang, Y.; Finsterle, S.
A simple conceptual model has been recently developed for analyzing pressure and temperature data from flowing fluid temperature logging (FFTL) in unsaturated fractured rock. Using this conceptual model, we developed an analytical solution for FFTL pressure response, and a semianalytical solution for FFTL temperature response. We also proposed a method for estimating fracture permeability from FFTL temperature data. The conceptual model was based on some simplifying assumptions, particularly that a single-phase airflow model was used. In this paper, we develop a more comprehensive numerical model of multiphase flow and heat transfer associated with FFTL. Using this numerical model, we perform a number of forward simulations to determine the parameters that have the strongest influence on the pressure and temperature response from FFTL. We then use the iTOUGH2 optimization code to estimate these most sensitive parameters through inverse modeling and to quantify the uncertainties associated with these estimated parameters. We conclude that FFTL can be utilized to determine permeability, porosity, and thermal conductivity of the fracture rock. Two other parameters, which are not properties of the fractured rock, have strong influence on FFTL response. These are pressure and temperature in the borehole that were at equilibrium with the fractured rock formation at the beginning of FFTL. We illustrate how these parameters can also be estimated from FFTL data.
Enhanced Geothermal Systems Research and Development: Models of Subsurface Chemical Processes Affecting Fluid Flow
Moller, Nancy; Weare J. H.
Successful exploitation of the vast amount of heat stored beneath the earth�s surface in hydrothermal and fluid-limited, low permeability geothermal resources would greatly expand the Nation�s domestic energy inventory and thereby promote a more secure energy supply, a stronger economy and a cleaner environment. However, a major factor limiting the expanded development of current hydrothermal resources as well as the production of enhanced geothermal systems (EGS) is insufficient knowledge about the chemical processes controlling subsurface fluid flow. With funding from past grants from the DOE geothermal program and other agencies, we successfully developed advanced equation of state (EOS) and simulation technologies that accurately describe the chemistry of geothermal reservoirs and energy production processes via their free energies for wide XTP ranges. Using the specific interaction equations of Pitzer, we showed that our TEQUIL chemical models can correctly simulate behavior (e.g., mineral scaling and saturation ratios, gas break out, brine mixing effects, down hole temperatures and fluid chemical composition, spent brine incompatibilities) within the compositional range (Na-K-Ca-Cl-SO4-CO3-H2O-SiO2-CO2(g)) and temperature range (T < 350�C) associated with many current geothermal energy production sites that produce brines with temperatures below the critical point of water. The goal of research carried out under DOE grant DE-FG36-04GO14300 (10/1/2004-12/31/2007) was to expand the compositional range of our Pitzer-based TEQUIL fluid/rock interaction models to include the important aluminum and silica interactions (T < 350�C). Aluminum is the third most abundant element in the earth�s crust; and, as a constituent of aluminosilicate minerals, it is found in two thirds of the minerals in the earth�s crust. The ability to accurately characterize effects of temperature, fluid mixing and interactions between major rock-forming minerals and hydrothermal and/or injected fluids is critical to predict important chemical behaviors affecting fluid flow, such as mineral precipitation/dissolution reactions. We successfully achieved the project goal and objectives by demonstrating the ability of our modeling technology to correctly predict the complex pH dependent solution chemistry of the Al3+ cation and its hydrolysis species: Al(OH)2+, Al(OH)2+, Al(OH)30, and Al(OH)4- as well as the solubility of common aluminum hydroxide and aluminosilicate minerals in aqueous brines containing components (Na, K, Cl) commonly dominating hydrothermal fluids. In the sodium chloride system, where experimental data for model parameterization are most plentiful, the model extends to 300�C. Determining the stability fields of aluminum species that control the solubility of aluminum-containing minerals as a function of temperature and composition has been a major objective of research in hydrothermal chemistry.
McKay, M.D.; Sweeney, C.E.; Spangler, B.S. Jr.
A flow meter and temperature measuring device are described comprising a tube with a body centered therein for restricting flow and a sleeve at the upper end of the tube to carry several channels formed longitudinally in the sleeve to the appropriate axial location where they penetrate the tube to allow pressure measurements and temperature measurements with thermocouples. The high pressure measurement is made using a channel penetrating the tube away from the body and the low pressure measurement is made at a location at the widest part of the body. An end plug seals the end of the device and holes at its upper end allow fluid to pass from the interior of the tube into a plenum. The channels are made by cutting grooves in the sleeve, the grooves widened at the surface of the sleeve and then a strip of sleeve material is welded to the grooves closing the channels. Preferably the sleeve is packed with powdered graphite before cutting the grooves and welding the strips. 7 figures.
McKay, Mark D. (1426 Socastee Dr., North Augusta, SC 29841); Sweeney, Chad E. (3600 Westhampton Dr., Martinez, GA 30907-3036); Spangler, Jr., B. Samuel (2715 Margate Dr., Augusta, GA 30909)
A flow meter and temperature measuring device comprising a tube with a body centered therein for restricting flow and a sleeve at the upper end of the tube to carry several channels formed longitudinally in the sleeve to the appropriate axial location where they penetrate the tube to allow pressure measurements and temperature measurements with thermocouples. The high pressure measurement is made using a channel penetrating the tube away from the body and the low pressure measurement is made at a location at the widest part of the body. An end plug seals the end of the device and holes at its upper end allow fluid to pass from the interior of the tube into a plenum. The channels are made by cutting grooves in the sleeve, the grooves widened at the surface of the sleeve and then a strip of sleeve material is welded to the grooves closing the channels. Preferably the sleeve is packed with powdered graphite before cutting the grooves and welding the strips.
Fast and Informative Flow Simulations in a Building by Using Fast Fluid Dynamics Model on Graphics Processing Unit
Chen, Qingyan "Yan"
Fast and Informative Flow Simulations in a Building by Using Fast Fluid Dynamics Model on Graphics solve Navier-Stokes equations and other transportation equations for energy and species at a speed of 50 it in parallel on a Graphics Processing Unit (GPU). This study validated the FFD on the GPU by simulating
Insertable fluid flow passage bridgepiece and method
Jones, Daniel O. (Glenville, NV)
A fluid flow passage bridgepiece for insertion into an open-face fluid flow channel of a fluid flow plate is provided. The bridgepiece provides a sealed passage from a columnar fluid flow manifold to the flow channel, thereby preventing undesirable leakage into and out of the columnar fluid flow manifold. When deployed in the various fluid flow plates that are used in a Proton Exchange Membrane (PEM) fuel cell, bridgepieces of this invention prevent mixing of reactant gases, leakage of coolant or humidification water, and occlusion of the fluid flow channel by gasket material. The invention also provides a fluid flow plate assembly including an insertable bridgepiece, a fluid flow plate adapted for use with an insertable bridgepiece, and a method of manufacturing a fluid flow plate with an insertable fluid flow passage bridgepiece.
Proper initial conditions for the lubrication model of the flow of a thin film of fluid
S. A. Suslov; A. J. Roberts
A lubrication model describes the dynamics of a thin layer of fluid spreading over a solid substrate. But to make forecasts we need to supply correct initial conditions to the model. Remarkably, the initial fluid thickness is not the correct initial thickness for the lubrication model. Theory recently developed in \\cite{Roberts89b,Roberts97b} provides the correct projection of initial conditions onto a model of a dynamical system. The correct projection is determined by requiring that the model's solution exponentially quickly approaches that of the actual fluid dynamics. For lubrication we show that although the initial free surface shape contributes the most to the model's initial conditions, the initial velocity field is also an influence. The projection also gives a rationale for incorporating miscellaneous small forcing effects into the lubrication model; gravitational forcing is given as one example.
A Site-Scale Model For Fluid And Heat Flow In The Unsaturated...
heat at Yucca Mountain, Nevada, a potential repository site for high-level radioactive waste. The model takes into account the simultaneous flow dynamics of liquid water, vapor,...
Unified formal reduction for fluid models of free-surface shallow gravity-flows
Paris-Sud XI, Universit� de
modelling of the rheology in e.g. mud flows and land- slides, which are still much investigated model provided the assumptions used for the derivation hold. We obtain a synthetic viewpoint of various
Impact of relative permeability models on fluid flow behavior for gas condensate reservoirs
Zapata Arango, Jose? Francisco
. 6 Integral from immiscible to miscible transition models for gas condensate relative permeability. 5 . 6 . . 8 9 . 10 . 12 . 16 . 18 . 20 . 23 CHAPTER III CASE STUDY. . . 27 3. 1 Tuning of the reservoir fluid model 3. 2 Relative... model . 5. 2. 2 Anisotropic model . 64 . 74 . 77 . 90 CHAPTER VI SUMMARY . 105 6. 1 Conclusions. . 6. 1. 1 Conclusions from the literature review and case study . . . . . . 6. 1. 2 Conclusions from the simulation study 6. 1. 3 Conclusions from...
Impact of relative permeability models on fluid flow behavior for gas condensate reservoirs�
Zapata Arango, Jose? Francisco
. 6 Integral from immiscible to miscible transition models for gas condensate relative permeability. 5 . 6 . . 8 9 . 10 . 12 . 16 . 18 . 20 . 23 CHAPTER III CASE STUDY. . . 27 3. 1 Tuning of the reservoir fluid model 3. 2 Relative... model . 5. 2. 2 Anisotropic model . 64 . 74 . 77 . 90 CHAPTER VI SUMMARY . 105 6. 1 Conclusions. . 6. 1. 1 Conclusions from the literature review and case study . . . . . . 6. 1. 2 Conclusions from the simulation study 6. 1. 3 Conclusions from...
Linked multicontinuum and crack tensor approach for modeling of coupled geomechanics, fluid flow and transport in fractured rock
Rutqvist, J.
and Mining Sciences & Geomechanics Abstracts, 1983, 20:and Mining Sciences & Geomechanics Abstracts, 1985, BerrymanL W. Coupling fluid flow and geomechanics in dual-porosity
Osinski, Charles Anthony
zero and unity. The Ostwald- de Waele Equation (4), commonly known as the power law, is sometimes used to describe fluid behavior of this type. The rheological equation is (4) where the parameters "k" and "n" are constant for a particular fluid... be extended to include Reynolds numbers and the type of flow determined to be laminar and/or turbulent. It is assumed that the transition from laminar to turbulent flow occurs at a Reynolds number of 2100, the numeric distribution of Reynolds numbers...
Analytical Models for Flowing-Fluid Temperature Distribution in Single-Phase Oil Reservoirs Accounting for Joule-Thomson Effect
Chevarunotai, Natasha
calculation. Findings from the sensitivity analysis allow us to make a decision whether or not to acquire more data or to perform additional tests for a more reasonable outcome- the flowing-fluid temperature in the reservoir. Bottomhole flowing...
Development of an equivalent homogenous fluid model for pseudo-two-phase (air plus water) flow through fractured rock
Price, J.; Indraratna, B. [University of Wollongong, Wollongong, NSW (Australia). School of Civil Engineering
Fracture flow of two-phase mixtures is particularly applicable to the coal mining and coal bed methane projects in Australia. A one-dimensional steady-state pseudo-two-phase flow model is proposed for fractured rock. The model considers free flow of a compressible mixture of air and water in an inclined planar fracture and is based upon the conservation of momentum and the 'cubic' law. The flow model is coupled to changes in the stress environment through the fracture normal stiffness, which is related to changes in fracture aperture. The model represents the individual air and water phases as a single equivalent homogenous fluid. Laboratory testing was performed using the two-phase high-pressure triaxial apparatus on 54 mm diameter (approximately 2: 1 height: diameter) borehole cores intersected by induced near-axial fractures. The samples were of Triassic arenaceous fine-medium grained sandstone (known as the Eckersley Formation) that is found locally in the Southern Coalfield of New South Wales. The sample fracture roughness was assessed using a technique based upon Fourier series analysis to objectively attribute a joint roughness coefficient. The proposed two-phase flow model was verified using the recorded laboratory data obtained over a range of triaxial confining pressures (i.e., fracture normal stresses).
Fluid Gravity Engineering Rocket motor flow analysis
Anand, Mahesh
Fluid Gravity Engineering Capability · Rocket motor flow analysis -Internal (performance) -External (plume / contamination) · Effect on landing site (surface alteration) -In-depth flow through porous young scientists/engineers Fluid Gravity Engineering Ltd #12;
Transient fluid and heat flow modeling in coupled wellbore/reservoir systems
Izgec, Bulent
....................................................... 66 5.3.1 Modeling Field Data ..................................................................... 68 5.3.2 Optimal Location of Permanent Downhole Gauge....................... 71 5.4 Effect of Gauge Location on Pressure-Transient Analysis... at the midpoint of the flow string................................. 70 Figure 5.26 Downhole gauge placement configurations .............................................. 71 Figure 5.27 Temperature and density profiles in the wellbore...
Physics-Based Low Order Galerkin Models in Fluid Dynamics & Flow Control
Gorban, Alexander N.
(Berlin Institute of Technology MB1, Germany) Marek Morzynski (Poznan University of Technology, Poland models of energy supply and consumption. Yet a third principle is the realization that governing flow to time-averaged energy dynamics of Galerkin modes, and gives rise to physically based, nonlinear sub
Santos, Juan
SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW J. E. Santos1, G. B. Savioli2, J. M. Carcione3, D´e, Argentina SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW p. #12;Introduction. I Storage of CO2). SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW p. #12;Introduction. II CO2 is separated from natural
Fluid Flow Simulation in Fractured Reservoirs
Sarkar, Sudipta
The purpose of this study is to analyze fluid flow in fractured reservoirs. In most petroleum reservoirs, particularly carbonate reservoirs and some tight sands, natural fractures play a critical role in controlling fluid ...
Process for retarding fluid flow
Sandford, B.B.; Zillmer, R.C.
A process is described for retarding the flow of fluid in a subterranean formation, comprising: (a) introducing an effective amount of a gel-forming composition into a subterranean formation, the gel-forming composition being operable when gelled in the formation for retarding the flow of fluid therein. The gel-forming composition consists of: i. a first substance dissolved in water to form an aqueous solution, the first substance being selected from the group consisting of polyvivyl alcohols, and mixtures thereof, wherein the gel-forming composition contains an amount of the first substance of from about 0.5 to about 5 weight percent of the gel-forming composition, and ii. an effective amount of glutaraldehyde which is operable for forming a weakly acidic condition having a pH from about 5.5 to less than 7 in the gel-forming composition and also operable for promoting crosslinking of the first substance and glutaraldehyde and for forming a gel from the gel-forming composition under the weakly acidic condition within a period of time no greater than about 5 days without adding an acidic catalyst to the gel-forming composition to lower the pH of the gel-forming composition below about 5.5.
Computational Fluid Dynamics Modeling of the Bonneville Project: Tailrace Spill Patterns for Low Flows and Corner Collector Smolt Egress
Rakowski, Cynthia L.; Serkowski, John A.; Richmond, Marshall C.; Perkins, William A.
In 2003, an extension of the existing ice and trash sluiceway was added at Bonneville Powerhouse 2 (B2). This extension started at the existing corner collector for the ice and trash sluiceway adjacent to Bonneville Powerhouse 2 and the new sluiceway was extended to the downstream end of Cascade Island. The sluiceway was designed to improve juvenile salmon survival by bypassing turbine passage at B2, and placing these smolt in downstream flowing water minimizing their exposure to fish and avian predators. In this study, a previously developed computational fluid dynamics model was modified and used to characterized tailrace hydraulics and sluiceway egress conditions for low total river flows and low levels of spillway flow. STAR-CD v4.10 was used for seven scenarios of low total river flow and low spill discharges. The simulation results were specifically examined to look at tailrace hydraulics at 5 ft below the tailwater elevation, and streamlines used to compare streamline pathways for streamlines originating in the corner collector outfall and adjacent to the outfall. These streamlines indicated that for all higher spill percentage cases (25% and greater) that streamlines from the corner collector did not approach the shoreline at the downstream end of Bradford Island. For the cases with much larger spill percentages, the streamlines from the corner collector were mid-channel or closer to the Washington shore as they moved downstream. Although at 25% spill at 75 kcfs total river, the total spill volume was sufficient to "cushion" the flow from the corner collector from the Bradford Island shore, areas of recirculation were modeled in the spillway tailrace. However, at the lowest flows and spill percentages, the streamlines from the B2 corner collector pass very close to the Bradford Island shore. In addition, the very flow velocity flows and large areas of recirculation greatly increase potential predator exposure of the spillway passed smolt. If there is concern for egress issues for smolt passing through the spillway, the spill pattern and volume need to be revisited.
, and pressure associated with each intra- and extracranial compartment (arteries and arterioles, capillary bed fluid volume] + ["other" volume]) is fixed [7]. Excellent mathematical results and insights, the assumption of fixed brain volume is not ac
SEISMIC MONITORING OF. CARBON DIOXIDE FLUID FLOW. J. E. Santos. 1. , G. B. Savioli. 2. , J. M. Carcione. 3. , D. Gei. 3. 1. CONICET, IGPUBA, Fac.
Characterizing fractured rock for fluid-flow, geomechanical, and paleostress modeling: Methods and preliminary results from Yucca Mountain, Nevada
Barton, C.C.; Larsen, E.; Page, W.R.; Howard, T.M.
Fractures have been characterized for fluid-flow, geomechanical, and paleostress modeling at three localities in the vicinity of drill hole USW G-4 at Yucca Mountain in southwestern Nevada. A method for fracture characterization is introduced that integrates mapping fracture-trace networks and quantifying eight fracture parameters: trace length, orientation, connectivity, aperture, roughness, shear offset, trace-length density, and mineralization. A complex network of fractures was exposed on three 214- to 260-m 2 pavements cleared of debris in the upper lithophysal unit of the Tiva Canyon Member of the Miocene Paint-brush Tuff. The pavements are two-dimensional sections through the three-dimensional network of strata-bound fractures. All fractures with trace lengths greater than 0.2 m were mapped and studied.
A computational model for viscous fluid flow, heat transfer, and melting in in situ vitrification melt pools
McHugh, P.R.; Ramshaw, J.D.
MAGMA is a FORTRAN computer code designed to viscous flow in in situ vitrification melt pools. It models three-dimensional, incompressible, viscous flow and heat transfer. The momentum equation is coupled to the temperature field through the buoyancy force terms arising from the Boussinesq approximation. All fluid properties, except density, are assumed variable. Density is assumed constant except in the buoyancy force terms in the momentum equation. A simple melting model based on the enthalpy method allows the study of the melt front progression and latent heat effects. An indirect addressing scheme used in the numerical solution of the momentum equation voids unnecessary calculations in cells devoid of liquid. Two-dimensional calculations can be performed using either rectangular or cylindrical coordinates, while three-dimensional calculations use rectangular coordinates. All derivatives are approximated by finite differences. The incompressible Navier-Stokes equations are solved using a new fully implicit iterative technique, while the energy equation is differenced explicitly in time. Spatial derivatives are written in conservative form using a uniform, rectangular, staggered mesh based on the marker and cell placement of variables. Convective terms are differenced using a weighted average of centered and donor cell differencing to ensure numerical stability. Complete descriptions of MAGMA governing equations, numerics, code structure, and code verification are provided. 14 refs.
This is a 1D model of an active magnetic regenerative refrigerator (AMRR) that was developed in MATLAB. The model uses cycle inputs such as the fluid mass flow and
Wisconsin at Madison, University of
This is a 1D model of an active magnetic regenerative refrigerator (AMRR) that was developed of an Active Magnetic Regenerator Refrigerator 1. Governing Equations Figure 1 shows a schematic of an active in MATLAB. The model uses cycle inputs such as the fluid mass flow and magnetic field profiles, fluid
Robust processing of optical flow of fluids Ashish Doshi and Adrian G. Bors, Senior Member, IEEE
Bors, Adrian
the computational fluid dynamics (CFD). Navier-Stokes equations have been extensively studied in fluid mechanics Terms--Optical flow of fluids, computational fluid dy- namics, diffusion, vortex detection I displaying fluid movement. Velocity fields, characterizing the motion of fluids can be modelled using
Modeling fluid flow through single fracture using experimental, stochastic, and simulation approaches
Alfred, Dicman
This research presents an approach to accurately simulate flow experiments through a fractured core using experimental, stochastic, and simulation techniques. Very often, a fracture is assumed as a set of smooth parallel plates separated by a...
Preferential mode of gas invasion in sediments : grain-scale model of coupled multiphase fluid flow and sediment mechanics
Jain, Antone Kumar
We present a discrete element model for simulating, at the grain scale, gas migration in brine-saturated deformable media. We rigorously account for the presence of two fluids in the pore space by incorporating forces on ...
Application of Neutron Imaging and Scattering to Fluid Flow and...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Application of Neutron Imaging and Scattering to Fluid Flow and Fracture in EGS Environments Application of Neutron Imaging and Scattering to Fluid Flow and Fracture in EGS...
Numerical modeling of fluid flow and time-lapse seismics to monitor ...
May 30, 2014 ... including the presence of shale seals and fractures and fractal variations of the ... In the Black-Oil model employed, brine is NOT present, OIL is.
Fluid flow control with transformation media
Urzhumov, Yaroslav A
We introduce a new concept for the manipulation of fluid flow around three-dimensional bodies. Inspired by transformation optics, the concept is based on a mathematical idea of coordinate transformations, and physically implemented with anisotropic porous media permeable to the flow of fluids. In two different situations - for an impermeable object situated either in a free-flowing fluid or in a fluid-filled porous medium - we show that the object can be coated with a properly chosen inhomogeneous, anisotropic permeable medium, such as to preserve the streamlines of flow and the pressure distribution that would have existed in the absence of the object. The proposed fluid flow cloak completely eliminates any disturbance of the flow by the object, including the downstream wake. Consequently, the structure helps prevent the onset of turbulence by keeping the flow laminar even above the typical critical Reynolds number for the object of the same shape and size. The cloak also cancels the viscous drag force. This...
Standardization of Thermo-Fluid Modeling in Modelica.Fluid
Franke, Rudiger; Casella, Francesco; Sielemann, Michael; Proelss, Katrin; Otter, Martin; Wetter, Michael
This article discusses the Modelica.Fluid library that has been included in the Modelica Standard Library 3.1. Modelica.Fluid provides interfaces and basic components for the device-oriented modeling of onedimensional thermo-fluid flow in networks containing vessels, pipes, fluid machines, valves and fittings. A unique feature of Modelica.Fluid is that the component equations and the media models as well as pressure loss and heat transfer correlations are decoupled from each other. All components are implemented such that they can be used for media from the Modelica.Media library. This means that an incompressible or compressible medium, a single or a multiple substance medium with one or more phases might be used with one and the same model as long as the modeling assumptions made hold. Furthermore, trace substances are supported. Modeling assumptions can be configured globally in an outer System object. This covers in particular the initialization, uni- or bi-directional flow, and dynamic or steady-state formulation of mass, energy, and momentum balance. All assumptions can be locally refined for every component. While Modelica.Fluid contains a reasonable set of component models, the goal of the library is not to provide a comprehensive set of models, but rather to provide interfaces and best practices for the treatment of issues such as connector design and implementation of energy, mass and momentum balances. Applications from various domains are presented.
Directed flow fluid rinse trough
Kempka, S.N.; Walters, R.N.
Novel rinse troughs accomplish thorough uniform rinsing. The tanks are suitable for one or more essentially planar items having substantially the same shape. The troughs ensure that each surface is rinsed uniformly. The new troughs also require less rinse fluid to accomplish a thorough rinse than prior art troughs. 9 figs.
Standardization of Thermo-Fluid Modeling in Modelica.Fluid
Franke, Rudiger
Ob- ject-Oriented Modeling of Thermo-Fluid Systems, Modelicable and Compressible Thermo-Fluid Pipe Networks, ModelicaStandardization of Thermo-Fluid Modeling in Modelica.Fluid
Flow control techniques for real-time media applications in best-effort networks using fluid models
Konstantinou, Apostolos
at the application layer. An end-to-end ?uid model is used, including the source bu?er, the network and the destination bu?er. Traditional con- trol techniques, along with more advanced adaptive predictive control methods, are considered in order to provide... OF THE END-TO-END FLOW TRANSPORT SYSTEM : : : : : : : : : : : : : : : : : : : : : : 25 A. Source Bu?er Model . . . . . . . . . . . . . . . . . . . . . 25 B. Network Dynamic Model . . . . . . . . . . . . . . . . . . . 27 1. Time-Varying Time Delay Model...
Method and apparatus for controlling fluid flow
Miller, J.R.
A method and apparatus for precisely controlling the rate (and hence amount) of fluid flow are given. The controlled flow rate is finely adjustable, can be extremely small (on the order of microliter-atmospheres per second), can be adjusted to zero (flow stopped), and is stable to better than 1% with time. The dead volume of the valve can be made arbitrarily small, in fact essentially zero. The valve employs no wearing mechanical parts (including springs, stems, or seals). The valve is finely adjustable, has a flow rate dynamic range of many decades, can be made compatible with any fluid, and is suitable for incorporation into an open or closed loop servo-control system.
Formulation and sequential numerical algorithms of coupled fluid/heat flow and geomechanics for multiple porosity materials
Kim, J.
Settari A. Modeling of geomechanics in naturally fracturedway coupled fluid flow and geomechanics in hydrate deposits.for coupled flow and geomechanics: Drained and undrained
Flow of Navier-Stokes Fluids in Cylindrical Elastic Tubes
Sochi, Taha
Analytical expressions correlating the volumetric flow rate to the inlet and outlet pressures are derived for the time-independent flow of Newtonian fluids in cylindrically-shaped elastic tubes using a one-dimensional Navier-Stokes flow model with two pressure-area constitutive relations. These expressions for elastic tubes are the equivalent of Poiseuille and Poiseuille-type expressions for rigid tubes which were previously derived for the flow of Newtonian and non-Newtonian fluids under various flow conditions. Formulae and procedures for identifying the pressure field and tube geometric profile are also presented. The results are validated by a finite element method implementation. Sensible trends in the analytical and numerical results are observed and documented.
Shear flow instabilities in viscoelastic fluids
Miller, Joel C.
- stabilities may be desirable: for example in microfluidics it may be necessary 2to mix two fluids together. This is made difficult by the small length scales and resulting low Reynolds number. An instability which mixes the entire flow is needed. Part I...
Computational Fluids Dynamics and its Application to Multiphase Flows (3 credits)
Chen, Zheng
Computational Fluids Dynamics and its Application to Multiphase Flows (3 credits) Instructor Eric CLIMENT, Dept. of Fluids Mechanics, INP-ENSEEIHT / IMFT (firstname.lastname@example.com) Synopsis Multiphase flows will be introduced, together with their applications to multiphase flows (dispersion, two-way coupling, modelling
Ultrasonic fluid flow measurement method and apparatus
Kronberg, J.W.
An apparatus for measuring the flow of a fluid in a pipe using ultrasonic waves. The apparatus comprises an ultrasonic generator, a lens for focusing the sound energy produced by the generator, and means for directing the focused energy into the side of the pipe through an opening and in a direction close to parallel to the long axis of the pipe. A cone carries the sound energy to the lens from the generator. Depending on the choice of materials, there may be a quarter-wave, acoustic impedance matching section between the generator and the cone to reduce the reflections of energy at the cone boundary. The lens material has an acoustic impedance similar to that of the cone material but a different sonic velocity so that the lens can converge the sound waves in the fluid. A transition section between the lens and the fluid helps to couple the energy to the fluid and assures it is directed as close to parallel to the fluid flow direction as possible. 3 figures.
Ultrasonic fluid flow measurement method and apparatus
Kronberg, James W. (108 Independent Blvd., Aiken, SC 29801)
An apparatus for measuring the flow of a fluid in a pipe using ultrasonic waves. The apparatus comprises an ultrasonic generator, a lens for focusing the sound energy produced by the generator, and means for directing the focused energy into the side of the pipe through an opening and in a direction close to parallel to the long axis of the pipe. A cone carries the sound energy to the lens from the generator. Depending on the choice of materials, there may be a quarter-wave, acoustic impedance matching section between the generator and the cone to reduce the reflections of energy at the cone boundary. The lens material has an acoustic impedance similar to that of the cone material but a different sonic velocity so that the lens can converge the sound waves in the fluid. A transition section between the lens and the fluid helps to couple the energy to the fluid and assures it is directed as close to parallel to the fluid flow direction as possible.
An Analysis of Heat and Fluid Flow Phenomena 1n Electroslag Welding
Eagar, Thomas W.
and temperature distri- bution~ are given for several idealized models of the electroslag welding process) ) An Analysis of Heat and Fluid Flow Phenomena 1n Electroslag Welding Two physical models created and fluid flow phenom- ena in metals processing operations have been applied to electroslag weld- ing
The Effects of Fluid Flow On Shear Localization and Frictional Strength From Dynamic Models Of Fault Gouge During Earthquakes
Bianco, Ronald
have an increased localization toward the boundaries of the gouge layer (type III), and no occurrence of distributed (type I) shear. Systems with lower N and k show liquefaction events. Liquefaction events originate from increases in fluid pressure...
Numerical simulation of two-phase fluid flow
diffusive wave (see also Carcione, 2007). Hence, fluid flow and pressure diffusion are phenomena described by the same differential equation. In hydrology and�...
Mathematical Modeling of Thermal-Fluid Flow in the Meniscus Region During An Oscillation Cycle Claudio Ojeda
Thomas, Brian G.
-mail:firstname.lastname@example.com Jose Luis Arana University of Basque Country C/Alameda de Urkijo S/N 48013-Bilbao(Vizcaya)-Spain Fax:+34-94-601-4180 E-mail:firstname.lastname@example.com Key words: Mold powder, Lubrication, Overflow, Slag rim, Fluid
Fluid flow plate for decreased density of fuel cell assembly
Vitale, Nicholas G. (Albany, NY)
A fluid flow plate includes first and second outward faces. Each of the outward faces has a flow channel thereon for carrying respective fluid. At least one of the fluids serves as reactant fluid for a fuel cell of a fuel cell assembly. One or more pockets are formed between the first and second outward faces for decreasing density of the fluid flow plate. A given flow channel can include one or more end sections and an intermediate section. An interposed member can be positioned between the outward faces at an interface between an intermediate section, of one of the outward faces, and an end section, of that outward face. The interposed member can serve to isolate the reactant fluid from the opposing outward face. The intermediate section(s) of flow channel(s) on an outward face are preferably formed as a folded expanse.
Multiscale Methods for Modeling Fluid Flow Through Naturally Fractured Carbonate Karst P. Popov, G. Qin, L. Bi, Y. Efendiev, R. Ewing, Institute for Scientific Computation, Texas A&M University; Z. Kang, J. Li,
Ewing, Richard E.
reservoir conditions, such as partially filled fractures. Introduction Naturally fractured karst reservoirsSPE 110778 Multiscale Methods for Modeling Fluid Flow Through Naturally Fractured Carbonate Karst Reservoirs P. Popov, G. Qin, L. Bi, Y. Efendiev, R. Ewing, Institute for Scientific Computation, Texas A
Scalable parallel methods for monolithic coupling in fluid-structure interaction with application to blood flow
Cai, Xiao-Chuan
to blood flow modeling 6 Andrew T. Barker,a , Xiao-Chuan Caib a Department of Applied Mathematics finite element solver for the simulation of blood flow in compliant arteries. The incompressible Navier-Stokes equations are used to model the fluid and coupled to an incom- pressible linear elastic model for the blood
Ewing, Richard E.
associated with two seem� ingly disparate applications: production of petroleum and the remediation of water procedures associated with injection and production wells. Equations to describe the flow of fluids in porous. Such data can include pressure and flow rates of various fluid phases obtained during production, or during
Analysis of multiphase fluid flows via high speed and synthetic aperture three dimensional imaging
Scharfman, Barry Ethan
Spray flows are a difficult problem within the realm of fluid mechanics because of the complicated interfacial physics involved. Complete models of sprays having even the simplest geometries continue to elude researchers ...
Linked multicontinuum and crack tensor approach for modeling of coupled geomechanics, fluid flow and transport in fractured rock
Rutqvist, J.
geomechanics in dual-porosity modeling of naturally fractured reservoirs. Society of Petroleum Engineers,
Method and apparatus for chemically altering fluids in continuous flow
Heath, W.O.; Virden, J.W. Jr.; Richardson, R.L.; Bergsman, T.M.
The present invention relates to a continuous flow fluid reactor for chemically altering fluids. The reactor operates on standard frequency (50 to 60 Hz) electricity. The fluid reactor contains particles that are energized by the electricity to form a corona throughout the volume of the reactor and subsequently a non-equilibrium plasma that interacts with the fluid. Particles may form a fixed bed or a fluid bed. Electricity may be provided through electrodes or through an inductive coil. Fluids include gases containing exhaust products and organic fuels requiring oxidation. 4 figures.
Method and apparatus for chemically altering fluids in continuous flow
Heath, William O. (Richland, WA); Virden, Jr., Judson W. (Richland, WA); Richardson, R. L. (West Richland, WA); Bergsman, Theresa M. (Richland, WA)
The present invention relates to a continuous flow fluid reactor for chemically altering fluids. The reactor operates on standard frequency (50 to 60 Hz) electricity. The fluid reactor contains particles that are energized by the electricity to form a corona throughout the volume of the reactor and subsequently a non-equilibrium plasma that interacts with the fluid. Particles may form a fixed bed or a fluid bed. Electricity may be provided through electrodes or through an inductive coil. Fluids include gases containing exhaust products and organic fuels requiring oxidation.
Numerical modeling of time-lapse seismic data from fractured reservoirs including fluid flow and geochemical processes�
Shekhar, Ravi
and amplitude variation with offset (AVO) results for our example model predicts that CO2 is easier to detect than brine in the fractured reservoirs. The effects of geochemical processes on seismics are simulated by time-lapse modeling for t = 1000 years. My...
A chaotic-dynamical conceptual model to describe fluid flow and contaminant transport in a fractured vadose zone. 1997 progress report and presentations at the annual meeting, Ernest Orlando Lawrence Berkeley National Laboratory, December 3--4, 1997
Faybishenko, B.; Doughty, C.; Geller, J. [and others
Understanding subsurface flow and transport processes is critical for effective assessment, decision-making, and remediation activities for contaminated sites. However, for fluid flow and contaminant transport through fractured vadose zones, traditional hydrogeological approaches are often found to be inadequate. In this project, the authors examine flow and transport through a fractured vadose zone as a deterministic chaotic dynamical process, and develop a model of it in these terms. Initially, the authors examine separately the geometric model of fractured rock and the flow dynamics model needed to describe chaotic behavior. Ultimately they will put the geometry and flow dynamics together to develop a chaotic-dynamical model of flow and transport in a fractured vadose zone. They investigate water flow and contaminant transport on several scales, ranging from small-scale laboratory experiments in fracture replicas and fractured cores, to field experiments conducted in a single exposed fracture at a basalt outcrop, and finally to a ponded infiltration test using a pond of 7 by 8 m. In the field experiments, they measure the time-variation of water flux, moisture content, and hydraulic head at various locations, as well as the total inflow rate to the subsurface. Such variations reflect the changes in the geometry and physics of water flow that display chaotic behavior, which they try to reconstruct using the data obtained. In the analysis of experimental data, a chaotic model can be used to predict the long-term bounds on fluid flow and transport behavior, known as the attractor of the system, and to examine the limits of short-term predictability within these bounds. This approach is especially well suited to the need for short-term predictions to support remediation decisions and long-term bounding studies. View-graphs from ten presentations made at the annual meeting held December 3--4, 1997 are included in an appendix to this report.
Maxwell's fluid model of magnetism
Robert Brady; Ross Anderson
In 1861, Maxwell derived two of his equations of electromagnetism by modelling a magnetic line of force as a `molecular vortex' in a fluid-like medium. Later, in 1980, Berry and colleagues conducted experiments on a `phase vortex', a wave geometry in a fluid which is analogous to a magnetic line of force and also exhibits behaviour corresponding to the quantisation of magnetic flux. Here we unify these approaches by writing down a solution to the equations of motion for a compressible fluid which behaves in the same way as a magnetic line of force. We then revisit Maxwell's historical inspiration, namely Faraday's 1846 model of light as disturbances in lines of force. Using our unified model, we show that such disturbances resemble photons: they are polarised, absorbed discretely, obey Maxwell's full equations of electromagnetism to first order, and quantitatively reproduce the correlation that is observed in the Bell tests.
Applying uncertainty quantification to multiphase flow computational fluid dynamics
Gel, A.; Garg, R.; Tong, C.; Shahnam, M.; Guenther, C.
Multiphase computational fluid dynamics plays a major role in design and optimization of fossil fuel based reactors. There is a growing interest in accounting for the influence of uncertainties associated with physical systems to increase the reliability of computational simulation based engineering analysis. The U.S. Department of Energy's National Energy Technology Laboratory (NETL) has recently undertaken an initiative to characterize uncertainties associated with computer simulation of reacting multiphase flows encountered in energy producing systems such as a coal gasifier. The current work presents the preliminary results in applying non-intrusive parametric uncertainty quantification and propagation techniques with NETL's open-source multiphase computational fluid dynamics software MFIX. For this purpose an open-source uncertainty quantification toolkit, PSUADE developed at the Lawrence Livermore National Laboratory (LLNL) has been interfaced with MFIX software. In this study, the sources of uncertainty associated with numerical approximation and model form have been neglected, and only the model input parametric uncertainty with forward propagation has been investigated by constructing a surrogate model based on data-fitted response surface for a multiphase flow demonstration problem. Monte Carlo simulation was employed for forward propagation of the aleatory type input uncertainties. Several insights gained based on the outcome of these simulations are presented such as how inadequate characterization of uncertainties can affect the reliability of the prediction results. Also a global sensitivity study using Sobol' indices was performed to better understand the contribution of input parameters to the variability observed in response variable.
Implementation of surface tension with wall adhesion effects in a three-dimensional finite element model for fluid flow
Boyer, Edmond
- 1 - Implementation of surface tension with wall adhesion effects in a three-dimensional finite element modelling of surface tension. The external stress vectors associated with surface tension a drop of liquid on a plane is treated. Keywords : surface tension, finite element method, average
Flow networks: A characterization of geophysical fluid transport
Enrico Ser-Giacomi; Vincent Rossi; Cristobal Lopez; Emilio Hernandez-Garcia
We represent transport between different regions of a fluid domain by flow networks, constructed from the discrete representation of the Perron-Frobenius or transfer operator associated to the fluid advection dynamics. The procedure is useful to analyze fluid dynamics in geophysical contexts, as illustrated by the construction of a flow network associated to the surface circulation in the Mediterranean sea. We use network-theory tools to analyze the flow network and gain insights into transport processes. In particular we quantitatively relate dispersion and mixing characteristics, classically quantified by Lyapunov exponents, to the degree of the network nodes. A family of network entropies is defined from the network adjacency matrix, and related to the statistics of stretching in the fluid, in particular to the Lyapunov exponent field. Finally we use a network community detection algorithm, Infomap, to partition the Mediterranean network into coherent regions, i.e. areas internally well mixed, but with little fluid interchange between them.
Controls on Fault-Hosted Fluid Flow: Preliminary Results from...
Geothermal Field, CA Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Proceedings: Controls on Fault-Hosted Fluid Flow: Preliminary Results from the...
On the acceleration potential in perfect fluid flow
Maestri, Raymond Rudolph
ON THE ACCELERATION POTENTIAL IN PERFECT FLUID FLOW A Thesis By RAYMOND RUDOLPH MAESTRI Submitted. to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfrllment of the requirements for the degree of MASTER... OF SCIENCE August, 1960 Department of Aeronautical Engineering Major Subject: Aeronautical Engineering ON THE ACCELERATION POTENTIAL IN PERFECT FLUID FLOW A Thesis RAYMOND RUDOLPH MAESTRI Approved as to style and content by: Chairman of Commit e...
Journal of Fluids and Structures 24 (2008) 250269 Numerical and experimental study of expiratory flow
Van Hirtum, Annemie
, the pharynx, the mouth and the larynx (Fig. 1), is the most external part of the respiratory system. Modelling deformations has been chosen to compute the mechanical behaviour of the tongue. The main features of the flow and Depollier, 1995; Huang, 1995; Balint and Lucey, 2005), numerical simulations of the respiratory fluid flow
1. Introduction Fluid flow in continuous casting of steel is of great inter-
Thomas, Brian G.
-phase fluid flow owing to the simulation kinematic viscosity of steel and water, the flow pattern itself and entrainment of the mold slag, · transient fluctuations and waves in the top surface level, and their effect, such as intermixing during a grade change and segregation. Extensive past work has employed physical water models
System and method measuring fluid flow in a conduit
Ortiz, Marcos German (Idaho Falls, ID); Kidd, Terrel G. (Blackfoot, ID)
A system for measuring fluid mass flow in a conduit in which there exists a pressure differential in the fluid between at least two spaced-apart locations in the conduit. The system includes a first pressure transducer disposed in the side of the conduit at a first location for measuring pressure of fluid at that location, a second or more pressure transducers disposed in the side of the conduit at a second location, for making multiple measurements of pressure of fluid in the conduit at that location, and a computer for computing the average pressure of the multiple measurements at the second location and for computing flow rate of fluid in the conduit from the pressure measurement by the first pressure transducer and from the average pressure calculation of the multiple measurements.
Numerical and experimental study of expiratory flow in the case of major upper airway obstructions with fluid-structure interaction
Paris-Sud XI, Universit� de
and the larynx (fig. 1), is the most external part of the respiratory system. Modelling the fluid flow is described. The theory of linear elasticity in small deformations has been chosen to compute the mechanical of the respiratory fluid flow (Shome et al., 1998; Allen et al., 2004; Xu et al., 2006; Sung et al., 2006; Liu et al
PAPER B3: PHYSICS OF FLUID FLOWS Hilary Term 2010
Read, Peter L.
,...) · Aerodynamics important advances in fluid dynamics c. 1900 still active today · Lubrication of mechanical systems · Industry e.g. gases in pipes, polymer flows · Oil extraction liquids flowing through eff n, where `effective diameter' deff 0.3 nm, say. 2 �? 10-7 m = 200 nm. In FD, we consider scales
Advanced tomographic flow diagnostics for opaque multiphase fluids
Torczynski, J.R.; O`Hern, T.J.; Adkins, D.R.; Jackson, N.B.; Shollenberger, K.A.
This report documents the work performed for the ``Advanced Tomographic Flow Diagnostics for Opaque Multiphase Fluids`` LDRD (Laboratory-Directed Research and Development) project and is presented as the fulfillment of the LDRD reporting requirement. Dispersed multiphase flows, particularly gas-liquid flows, are industrially important to the chemical and applied-energy industries, where bubble-column reactors are employed for chemical synthesis and waste treatment. Due to the large range of length scales (10{sup {minus}6}-10{sup 1}m) inherent in real systems, direct numerical simulation is not possible at present, so computational simulations are forced to use models of subgrid-scale processes, the accuracy of which strongly impacts simulation fidelity. The development and validation of such subgrid-scale models requires data sets at representative conditions. The ideal measurement techniques would provide spatially and temporally resolved full-field measurements of the distributions of all phases, their velocity fields, and additional associated quantities such as pressure and temperature. No technique or set of techniques is known that satisfies this requirement. In this study, efforts are focused on characterizing the spatial distribution of the phases in two-phase gas-liquid flow and in three-phase gas-liquid-solid flow. Due to its industrial importance, the bubble-column geometry is selected for diagnostics development and assessment. Two bubble-column testbeds are utilized: one at laboratory scale and one close to industrial scale. Several techniques for measuring the phase distributions at conditions of industrial interest are examined: level-rise measurements, differential-pressure measurements, bulk electrical impedance measurements, electrical bubble probes, x-ray tomography, gamma-densitometry tomography, and electrical impedance tomography.
Method, apparatus and system for controlling fluid flow
McMurtrey, Ryan D. (Idaho Falls, ID); Ginosar, Daniel M. (Idaho Falls, ID); Burch, Joesph V. (Shelley, ID)
A system, apparatus and method of controlling the flow of a fluid are provided. In accordance with one embodiment of the present invention, a flow control device includes a valve having a flow path defined therethrough and a valve seat in communication with the flow path with a valve stem disposed in the valve seat. The valve stem and valve seat are cooperatively configured to cause mutual relative linear displacement thereof in response to rotation of the valve stem. A gear member is coupled with the rotary stem and a linear positioning member includes a portion which complementarily engages the gear member. Upon displacement of the linear positioning member along a first axis, the gear member and rotary valve stem are rotated about a second axis and the valve stem and valve seat are mutually linearly displaced to alter the flow of fluid through the valve.
Flow of fractal fluid in pipes: Non-integer dimensional space Vasily E. Tarasov
Tarasov, Vasily E.
Flow of fractal fluid in pipes: Non-integer dimensional space approach Vasily E. Tarasov of an incompressible viscous fractal fluid in the pipe. Fractal fluid is described as a continuum in non solution for steady flow of fractal fluid in a pipe and corresponding fractal fluid discharge are suggested
Prediction of fluid flow in curved pipe using the finite element method
Maitin, Christopher Benjamin
. Therefore mathematical models have been developed to simulate the elfect of these stresses on the flow field. Until recently these models have only been used for simple geometries. With the advancement of the computer, numerical methods have been de... OF SCIENCE May 1987 Major Subject: Mechanical Engineering PREDICTION OF FLUID FLOW IN CURVED PIPE USING THE FINITE ELEMENT METHOD A Thesis CHRISTOPHER B. MAITIN Approved as to style and content by: Dennis L. O'Neal (Chairman of Committee) Warren...
Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation
Paris-Sud XI, Université de
Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation Conditions)" #12;Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation Conditions, cavitation, fluid flow load, CFD. Abstract: The evaluation of fluid forces on the stem is important for wear
Design considerations for inverters in fluid flow control
Guggari, Mallappa Ishwarappa
of Electric Drives for Fluid Flow Control D. Selection of Drive for Fluid Flow Application IV POWER CIRCUIT DESIGN CONSIDERATIONS 26 29 43 47 48 A. Torque Considerations B. Overload Current C. Voltage Considerations D. Power Factor E. Harmonics F... Equivalent circuit for a separately excited dc motor 3. 2 DC Drive control system 3. 3 Equivalent circuit of an Induction Motor 3. 4 Torque-speed curve of an Induction Motor 3. 5 Torque-speed curves of an Induction Motor with variable stator voltage...
Development of an analytical model for organic-fluid fouling
Panchal, C.B.; Watkinson, A.P.
The research goal of this project is to determine ways to effectively mitigate fouling in organic fluids: hydrocarbons and derived fluids. The fouling research focuses on the development of methodology for determining threshold conditions for fouling. Initially, fluid containing chemicals known to produce foulant is analyzed; subsequently, fouling of industrial fluids is investigated. The fouling model developed for determining the effects of physical parameters is the subject of this report. The fouling model is developed on the premise that the chemical reaction for generation of precursor can take place in the bulk fluid, in the thermal-boundary layer, or at the fluid/wall interface, depending upon the interactive effects of fluid dynamics, heat and mass transfer, and the controlling chemical reaction. In the analysis, the experimental data are examined for fouling deposition of polyperoxide produced by autoxidation of indene in kerosene. The effects of fluid and wall temperatures for two flow geometries are analyzed. The results show that the relative effects of physical parameters on the fouling rate differ for the three fouling mechanisms. Therefore, to apply the closed-flow-loop data to industrial conditions, the controlling mechanism must be identified.
SUBMITTED TO THE INTERNATIONAL JOURNAL OF FLOW CONTROL, REVISED VERSION 1 Fluid Flow Control: a Vision-Based Approach
Paris-Sud XI, Universit� de
SUBMITTED TO THE INTERNATIONAL JOURNAL OF FLOW CONTROL, REVISED VERSION 1 Fluid Flow Control, by visualizing a fluid flow, dense flow velocity maps can be computed via optical flow techniques by diminishing the fuel consumption of their aircrafts through drag reduction [1]. In contrast, in other
Characterization of fracture networks for fluid flow analysis
Long, J.C.S.; Billaux, D.; Hestir, K.; Majer, E.L.; Peterson, J.; Karasaki, K.; Nihei, K.; Gentier, S.; Cox, L.
The analysis of fluid flow through fractured rocks is difficult because the only way to assign hydraulic parameters to fractures is to perform hydraulic tests. However, the interpretation of such tests, or ''inversion'' of the data, requires at least that we know the geometric pattern formed by the fractures. Combining a statistical approach with geophysical data may be extremely helpful in defining the fracture geometry. Cross-hole geophysics, either seismic or radar, can provide tomograms which are pixel maps of the velocity or attenuation anomalies in the rock. These anomalies are often due to fracture zones. Therefore, tomograms can be used to identify fracture zones and provide information about the structure within the fracture zones. This structural information can be used as the basis for simulating the degree of fracturing within the zones. Well tests can then be used to further refine the model. Because the fracture network is only partially connected, the resulting geometry of the flow paths may have fractal properties. We are studying the behavior of well tests under such geometry. Through understanding of this behavior, it may be possible to use inverse techniques to refine the a priori assignment of fractures and their conductances such that we obtain the best fit to a series of well test results simultaneously. The methodology described here is under development and currently being applied to several field sites. 4 refs., 14 figs.
Sen, Mihir
= heat, f = LO-mode, g = LO, h = LA-mode, i = negligible, j = remote heat sink 7/ 70 #12;Heat conductionFLUID MECHANICS AND HEAT TRANSFER OF ELECTRON FLOW IN SEMICONDUCTORS Mihir Sen Department · Shallow water analogy · Vorticity dynamics · Linear stability analysis · Numerical simulations of heat
Fully Coupled Well Models for Fluid Injection and Production
White, Mark D.; Bacon, Diana H.; White, Signe K.; Zhang, Z. F.
Wells are the primary engineered component of geologic sequestration systems with deep subsurface reservoirs. Wells provide a conduit for injecting greenhouse gases and producing reservoirs fluids, such as brines, natural gas, and crude oil, depending on the target reservoir. Well trajectories, well pressures, and fluid flow rates are parameters over which well engineers and operators have control during the geologic sequestration process. Current drilling practices provided well engineers flexibility in designing well trajectories and controlling screened intervals. Injection pressures and fluids can be used to purposely fracture the reservoir formation or to purposely prevent fracturing. Numerical simulation of geologic sequestration processes involves the solution of multifluid transport equations within heterogeneous geologic media. These equations that mathematically describe the flow of fluid through the reservoir formation are nonlinear in form, requiring linearization techniques to resolve. In actual geologic settings fluid exchange between a well and reservoir is a function of local pressure gradients, fluid saturations, and formation characteristics. In numerical simulators fluid exchange between a well and reservoir can be specified using a spectrum of approaches that vary from totally ignoring the reservoir conditions to fully considering reservoir conditions and well processes. Well models are a numerical simulation approach that account for local conditions and gradients in the exchange of fluids between the well and reservoir. As with the mathematical equations that describe fluid flow in the reservoir, variation in fluid properties with temperature and pressure yield nonlinearities in the mathematical equations that describe fluid flow within the well. To numerically simulate the fluid exchange between a well and reservoir the two systems of nonlinear multifluid flow equations must be resolved. The spectrum of numerical approaches for resolving these equations varies from zero coupling to full coupling. In this paper we describe a fully coupled solution approach for well model that allows for a flexible well trajectory and screened interval within a structured hexahedral computational grid. In this scheme the nonlinear well equations have been fully integrated into the Jacobian matrix for the reservoir conservation equations, minimizing the matrix bandwidth.
Non-Steady wall-bounded flows of viscoelastic fluids under periodic forcing
Anier Hern�ndez-Garc�a; Antonio Fern�ndez-Barbero; Oscar Sotolongo-Costa
The problem of oscillating flows inside pipes under periodic forcing of viscoelastic fluids is addressed here. Starting from the linear Oldroyd-B model, a generalized Darcy's law is obtained in frequency domain and an explicit expression for the dependence of the dynamic permeability on fluid parameters and forcing frequency is derived. Previous results in both viscoelastic and Newtonian fluids are here shown to be particular cases of our results. On the basis of our calculations, a possible explanation for the observed damping of local dynamic response as the forcing frequency increases is given. Good fitting with recent experimental studies of wave propagation in viscoelastic media is here exhibited. Sound wave propagation in viscoelastic media flowing inside straight pipes is investigated. In particular, we obtain the local dynamic response for weakly compressible flows.
Effect of Fluid Flow on Inclusion Coarsening in Low-Alloy Steel Welds
Babu, S.S.; David, S.A.; DebRoy, T.; Hong, T.
Oxide inclusions form in welds because of deoxidation reactions in the weld pool. These inclusions control the weld microstructure development. Thermodynamic and kinetic calculation of oxidation reaction can describe inclusion characteristics such as number density, size, and composition. Experimental work has shown that fluid-flow velocity gradients in the weld pool can accelerate inclusion growth by collision and coalescence. Moreover, fluid flow in welds can transport inclusions to different temperature regions that may lead to repeated dissolution and growth of inclusions. These phenomena are being studied with the help of computational coupled heat transfer, fluid-flow, thermodynamic, and kinetic models. The results show that the inclusion formation in steel welds can be described as a function of the welding processes, process parameters, and steel composition.
Resistance of louvers to fluid flow
Bevier, Charles Wayland
as with shape and postion. This may be explained by the fact that geomet- rical similarity does not necessarily irqply mechanical similarity It has been proved that mechanical similarity with a given geometrical similarity is insured only if the ratio... arrangement. Table I gives a summary of the various louver arrangements tested. The maximum rate of air flow through the louver de- pended upon the output of the centrifugal fan used for the air source, For wide spacing of the louver boards (large free...
Garbe, Christoph S.
BAYESIAN INFERENCE ON INTEGRATED CONTINUITY FLUID FLOWS AND THEIR APPLICATION TO DUST AEROSOLS Waterloo, Ontario, Canada ABSTRACT The significant role dust aerosols play in the earth's cli- mate system models for aerosol de- tection and atmospheric transport that rely on latent Gaussian Markov random
Theoretical and Numerical Simulation of Non-Newtonian Fluid Flow in Propped Fractures
Ouyang, Liangchen
the original gel. The residual gel exhibits a higher yield stress, and is difficult to remove after fracture closure. But non-Newtonian fluid has complicated rheological equation and its flow behavior in porous media is difficult to be described and modeled...
A Numerical Algorithm for Fluid Flow in 3D Naturally Fractured Porous Media
Kentucky, University of
. Such fractured reservoirs could be modeled by permitting the porosity and permeability to vary rapidly as if the reservoir has two porous structures, one for the fractures and the other for the matrix blocksA Numerical Algorithm for Fluid Flow in 3D Naturally Fractured Porous Media Seongjai Kim Abstract
A splitting method for numerical simulation of free surface flows of incompressible fluids with surface tension
Olshanskii, Maxim A.
with surface tension Kirill D. Nikitin Maxim A. Olshanskii Kirill M. Terekhov Yuri V. Vassilevski§ Abstract to surface tension forces. The method splits one time step into a semi-Lagrangian treatment of the surface models a free surface flow of viscous incompressible fluid subject to surface tension forces. Further
Application of x-ray microtomography to environmental fluid flow D. Wildenschild*a,c
Wildenschild, Dorthe
of fluids in pores ultimately controls subsurface flow and contaminant transport relevant to groundwater-scale measurements make it possible to test existing and new theory, as well as emerging numerical modeling schemes, capillary pressure-saturation relationship 1. INTRODUCTION One of the most difficult and puzzling
Device and method for measuring multi-phase fluid flow in a conduit using an elbow flow meter
Ortiz, Marcos G. (Idaho Falls, ID); Boucher, Timothy J. (Helena, MT)
A system for measuring fluid flow in a conduit. The system utilizes pressure transducers disposed generally in line upstream and downstream of the flow of fluid in a bend in the conduit. Data from the pressure transducers is transmitted to a microprocessor or computer. The pressure differential measured by the pressure transducers is then used to calculate the fluid flow rate in the conduit. Control signals may then be generated by the microprocessor or computer to control flow, total fluid dispersed, (in, for example, an irrigation system), area of dispersal or other desired effect based on the fluid flow in the conduit.
Device and method for measuring multi-phase fluid flow in a conduit using an elbow flow meter
Ortiz, M.G.; Boucher, T.J.
A system is described for measuring fluid flow in a conduit. The system utilizes pressure transducers disposed generally in line upstream and downstream of the flow of fluid in a bend in the conduit. Data from the pressure transducers is transmitted to a microprocessor or computer. The pressure differential measured by the pressure transducers is then used to calculate the fluid flow rate in the conduit. Control signals may then be generated by the microprocessor or computer to control flow, total fluid dispersed, (in, for example, an irrigation system), area of dispersal or other desired effect based on the fluid flow in the conduit. 2 figs.
Preserving the Volume of Fluid Using Multi-phase Flow Approach Roman Durikovic
Durikovic, Roman
complex behaviors. We often see rising bubbles or flow of muddy water, such flows involve sev- eral fluids volume when the fluid passes through a donor cell to an acceptor cell. The VOF method was improved
Fluid-elastic Instability of Helical Tubes Subjected to Single-Phase External Flow and Two-Phase Internal Flow
Jong Chull Jo; Myung Jo Jhung; Woong Sik Kim; Hho Jung Kim [Korea Institute of Nuclear Safety, 19 Kusung-dong, Yusung-gu, Taejon 305-338 (Korea, Republic of)
This study investigates the fluid-elastic instability characteristics of steam generator helical type tubes in operating nuclear power plants. The thermal-hydraulic conditions of both tube side and shell side flow fields are predicted by a general purpose computational fluid dynamics code employing the finite volume element modeling. To get the natural frequency, corresponding mode shape and participation factor, modal analyses are performed for helical type tubes with various conditions. Investigated are the effects of the helix angle, the number of supports and the status of the inner fluid on the modal, and fluid-elastic instability characteristics of the tubes, which are expressed in terms of the natural frequency, corresponding mode shape, and stability ratio. (authors)
Noninvasive characterization of a flowing multiphase fluid using ultrasonic interferometry
Sinha, Dipen N. (Los Alamos, NM)
An apparatus for noninvasively monitoring the flow and/or the composition of a flowing liquid using ultrasound is described. The position of the resonance peaks for a fluid excited by a swept-frequency ultrasonic signal have been found to change frequency both in response to a change in composition and in response to a change in the flow velocity thereof. Additionally, the distance between successive resonance peaks does not change as a function of flow, but rather in response to a change in composition. Thus, a measurement of both parameters (resonance position and resonance spacing), once calibrated, permits the simultaneous determination of flow rate and composition using the apparatus and method of the present invention.
Noninvasive characterization of a flowing multiphase fluid using ultrasonic interferometry
Sinha, Dipen N.
An apparatus for noninvasively monitoring the flow and/or the composition of a flowing liquid using ultrasound is described. The position of the resonance peaks for a fluid excited by a swept-frequency ultrasonic signal have been found to change frequency both in response to a change in composition and in response to a change in the flow velocity thereof. Additionally, the distance between successive resonance peaks does not change as a function of flow, but rather in response to a change in composition. Thus, a measurement of both parameters (resonance position and resonance spacing), once calibrated, permits the simultaneous determination of flow rate and composition using the apparatus and method of the present invention.
Noninvasive Characterization Of A Flowing Multiphase Fluid Using Ultrasonic Interferometry
Sinha, Dipen N. (Los Alamos, NM)
An apparatus for noninvasively monitoring the flow and/or the composition of a flowing liquid using ultrasound is described. The position of the resonance peaks for a fluid excited by a swept-frequency ultrasonic signal have been found to change frequency both in response to a change in composition and in response to a change in the flow velocity thereof. Additionally, the distance between successive resonance peaks does not change as a function of flow, but rather in response to a change in composition. Thus, a measurement of both parameters (resonance position and resonance spacing), once calibrated, permits the simultaneous determination of flow rate and composition using the apparatus and method of the present invention.
Daripa, Prabir
FLUID DYNAMICAL AND MODELING ISSUES OF CHEMICAL FLOODING FOR ENHANCED OIL RECOVERY Prabir Daripa developed flows in enhanced oil recovery (EOR). In a recent exhaustive study [Transport in Porous Media, 93 fluid flows that occur in porous media during tertiary dis- placement process of chemical enhanced oil
Standardization of Thermo-Fluid Modeling in Modelica.Fluid
Franke, Rudiger
Thermo-Fluid Systems, Modelica 2003 Conference, Link�ping,H. Tummescheit: The Modelica Fluid and Media Library forThermo-Fluid Pipe Networks, Modelica 2006 Conference, Vi-
Internat. Congress on Science & Technology of Steelmaking, Charlotte, NC, May 9-12, AIST, Warrendale, PA, 2005, pp. 847-861. Modeling of Continuous-Casting Defects Related to Mold Fluid Flow
Thomas, Brian G.
that is neither too cold nor too turbulent. In addition, the flow conditions should minimize exposure to air optimization. Fluid flow in the mold is controlled by many design parameters and operating conditions. Nozzle geometry is the most important, and includes the bore size, port angle, port opening size, nozzle wall
Reducing or stopping the uncontrolled flow of fluid such as oil from a well
Hermes, Robert E
The uncontrolled flow of fluid from an oil or gas well may be reduced or stopped by injecting a composition including 2-cyanoacrylate ester monomer into the fluid stream. Injection of the monomer results in a rapid, perhaps instantaneous, polymerization of the monomer within the flow stream of the fluid. This polymerization results in formation of a solid plug that reduces or stops the flow of additional fluid from the well.
Reduced order modeling of fluid/structure interaction.
Barone, Matthew Franklin; Kalashnikova, Irina; Segalman, Daniel Joseph; Brake, Matthew Robert
This report describes work performed from October 2007 through September 2009 under the Sandia Laboratory Directed Research and Development project titled 'Reduced Order Modeling of Fluid/Structure Interaction.' This project addresses fundamental aspects of techniques for construction of predictive Reduced Order Models (ROMs). A ROM is defined as a model, derived from a sequence of high-fidelity simulations, that preserves the essential physics and predictive capability of the original simulations but at a much lower computational cost. Techniques are developed for construction of provably stable linear Galerkin projection ROMs for compressible fluid flow, including a method for enforcing boundary conditions that preserves numerical stability. A convergence proof and error estimates are given for this class of ROM, and the method is demonstrated on a series of model problems. A reduced order method, based on the method of quadratic components, for solving the von Karman nonlinear plate equations is developed and tested. This method is applied to the problem of nonlinear limit cycle oscillations encountered when the plate interacts with an adjacent supersonic flow. A stability-preserving method for coupling the linear fluid ROM with the structural dynamics model for the elastic plate is constructed and tested. Methods for constructing efficient ROMs for nonlinear fluid equations are developed and tested on a one-dimensional convection-diffusion-reaction equation. These methods are combined with a symmetrization approach to construct a ROM technique for application to the compressible Navier-Stokes equations.
Extended fluid models: Pressure tensor effects and equilibria
Cerri, S. S. [Physics Department �E. Fermi,� University of Pisa and CNISM, Largo B. Pontecorvo 3, 56127 Pisa (Italy) [Physics Department �E. Fermi,� University of Pisa and CNISM, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Max-Planck-Institut f�r Plasmaphysik, EURATOM association, Boltzmannstr. 2, D-85748 Garching (Germany); Henri, P. [Physics Department �E. Fermi,� University of Pisa and CNISM, Largo B. Pontecorvo 3, 56127 Pisa (Italy) [Physics Department �E. Fermi,� University of Pisa and CNISM, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Universit� de Nice Sophia Antipolis, CNRS, Observatoire de la C�te d'Azur, BP 4229 06304, Nice Cedex 4 (France); Califano, F.; Pegoraro, F. [Physics Department �E. Fermi,� University of Pisa and CNISM, Largo B. Pontecorvo 3, 56127 Pisa (Italy)] [Physics Department �E. Fermi,� University of Pisa and CNISM, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Del Sarto, D. [Institut Jean Lamour, UMR 7198 CNRS � Universit� de Lorraine, BP 239 F-54506 Vandoeuvre les Nancy (France)] [Institut Jean Lamour, UMR 7198 CNRS � Universit� de Lorraine, BP 239 F-54506 Vandoeuvre les Nancy (France); Faganello, M. [International Institute for Fusion Science/PIIM, UMR 7345 CNRS Aix-Marseille University, Marseille (France)] [International Institute for Fusion Science/PIIM, UMR 7345 CNRS Aix-Marseille University, Marseille (France)
We consider the use of �extended fluid models� as a viable alternative to computationally demanding kinetic simulations in order to manage the global large scale evolution of a collisionless plasma while accounting for the main effects that come into play when spatial micro-scales of the order of the ion inertial scale d{sub i} and of the thermal ion Larmor radius ?{sub i} are formed. We present an extended two-fluid model that retains finite Larmor radius (FLR) corrections to the ion pressure tensor while electron inertia terms and heat fluxes are neglected. Within this model we calculate analytic FLR plasma equilibria in the presence of a shear flow and elucidate the role of the magnetic field asymmetry. Using a Hybrid Vlasov code, we show that these analytic equilibria offer a significant improvement with respect to conventional magnetohydrodynamic shear-flow equilibria when initializing kinetic simulations.
Production of Natural Gas and Fluid Flow in Tight Sand Reservoirs
Maria Cecilia Bravo
This document reports progress of this research effort in identifying relationships and defining dependencies between macroscopic reservoir parameters strongly affected by microscopic flow dynamics and production well performance in tight gas sand reservoirs. These dependencies are investigated by identifying the main transport mechanisms at the pore scale that should affect fluids flow at the reservoir scale. A critical review of commercial reservoir simulators, used to predict tight sand gas reservoir, revealed that many are poor when used to model fluid flow through tight reservoirs. Conventional simulators ignore altogether or model incorrectly certain phenomena such as, Knudsen diffusion, electro-kinetic effects, ordinary diffusion mechanisms and water vaporization. We studied the effect of Knudsen's number in Klinkenberg's equation and evaluated the effect of different flow regimes on Klinkenberg's parameter b. We developed a model capable of explaining the pressure dependence of this parameter that has been experimentally observed, but not explained in the conventional formalisms. We demonstrated the relevance of this, so far ignored effect, in tight sands reservoir modeling. A 2-D numerical simulator based on equations that capture the above mentioned phenomena was developed. Dynamic implications of new equations are comprehensively discussed in our work and their relative contribution to the flow rate is evaluated. We performed several simulation sensitivity studies that evidenced that, in general terms, our formalism should be implemented in order to get more reliable tight sands gas reservoirs' predictions.
Stable loosely-coupled-type algorithm for fluid-structure interaction in blood flow
Guidoboni, Giovanna
Stable loosely-coupled-type algorithm for fluid-structure interaction in blood flow Giovanna Abstract We introduce a novel loosely coupled-type algorithm for fluid-structure interaction between blood. A major application is blood flow in human arteries. Understanding fluid- structure interaction between
Finite volume methods for fluid flow in porous media
Hiptmair, Ralf
. . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.5 Multiphase and multicomponent flows . . . . . . . . . . . . . . . 13 2.5.1 Black-oil model . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.3.1 General solution . . . . . . . . . . . . . . . . . . . . . . . 9 2.3.2 Pressure equation . . . . . . . . . . . . . . . . . . . . . . 10 2.3.3 Pressure equation for incompressible immiscible flow . . . 11 2.3.4 Saturation equation
Influence of formation clays on the flow of aqueous fluids
Hower, W.F.
Most sandstone formations contain clays that can have a significant effect on the flow of aqueous fluids. The clays most frequently detected are smectite, mixed layer, illite, kaolinite, and chlorite. All of these clays are capable of migrating and causing permeability damage when they are contacted by waters foreign to the formation. Normally, these waters alter ionic environments around the clays, which causes the clays to be dislodged from their original positions. Thus, any time clay is present in the rock, it can be assumed that permeability damage can occur. The degree of damage depends upon the concentration and types of clays present, their relative position in the rock, the severity of the ionic environmental change; and fluid velocity. Permeability damage has been minimized in oil and gas wells through the use of potassium and ammonium ions. 15 references.
Parcel EulerianLagrangian fluid dynamics of rotating geophysical flows
Oliver, Marcel
, Gottwald, and Reich (2002) and Frank and Reich (2003, 2004) introduced a Hamiltonian Particle Mesh (HPM integra- tion scheme is used. The HPM method is a parcel Eulerian�Lagrangian method: the fluid particles on the advection time scale. The conservation of mass and circulation in the HPM numerical model is shown
Volume-averaged macroscopic equation for fluid flow in moving porous media
Wang, Liang; Guo, Zhaoli; Mi, Jianchun
Darcy's law and the Brinkman equation are two main models used for creeping fluid flows inside moving permeable particles. For these two models, the time derivative and the nonlinear convective terms of fluid velocity are neglected in the momentum equation. In this paper, a new momentum equation including these two terms are rigorously derived from the pore-scale microscopic equations by the volume-averaging method, which can reduces to Darcy's law and the Brinkman equation under creeping flow conditions. Using the lattice Boltzmann equation method, the macroscopic equations are solved for the problem of a porous circular cylinder moving along the centerline of a channel. Galilean invariance of the equations are investigated both with the intrinsic phase averaged velocity and the phase averaged velocity. The results demonstrate that the commonly used phase averaged velocity cannot serve as the superficial velocity, while the intrinsic phase averaged velocity should be chosen for porous particulate systems.
Derivation of Newton's Law of Gravitation Based on a Fluid Mechanical Singularity Model of Particles
Xiao-Song Wang
We speculate that the universe may be filled with a kind of fluid which may be called aether or tao. Thus, Newton's law of gravitation is derived by methods of hydrodynamics based on a sink flow model of particles.
arXiv:1301.0752v1[physics.flu-dyn]4Jan2013 Fluid-particle flow modelling and validation using
Luding, Stefan
-way-coupled mesoscale SPH-DEM Martin Robinsona, , Stefan Ludinga , Marco Ramaiolib aMultiscale Mechanics, University required to resolve the pore-scale is too great. It then becomes necessary to use unresolved, or mesoscale, fluid simulations. This mesoscale is the focus of this paper and the domain of applicability for the SPH
A pair of superconducting interaction region quadrupole magnets for BEPCII was designed and fabricated at Brookhaven National Laboratory, USA. The cryogenic system for the IR magnets was designed at Harbin Institute of Technology, China. This paper provides the results of thermal fluid modeling for the magnet cryostat. The numerical analyses were carried out for two types of cooling methods, the subcooled liquid helium and the supercritical helium flow. The pressure and temperature changes in the cooling circuits are given.
Microscale Fluid Flow Induced by Thermoviscous Expansion Along a Traveling Wave Franz M. Weinert,1
Kersting, Roland
are negli- gible if the velocities are small with respect to the speed of sound, fluid flow is essentially confinement of a liquid changes its flow behavior markedly since the importance of surface forces relative a novel mechanism to generate net flow in a thin fluid chamber, i.e., a viscous liquid confined between
A Finite-Difference Numerical Method for Onsager's Pancake Approximation for Fluid Flow in a Gas Centrifuge
de Stadler, M; Chand, K
Gas centrifuges exhibit very complex flows. Within the centrifuge there is a rarefied region, a transition region, and a region with an extreme density gradient. The flow moves at hypersonic speeds and shock waves are present. However, the flow is subsonic in the axisymmetric plane. The analysis may be simplified by treating the flow as a perturbation of wheel flow. Wheel flow implies that the fluid is moving as a solid body. With the very large pressure gradient, the majority of the fluid is located very close to the rotor wall and moves at an azimuthal velocity proportional to its distance from the rotor wall; there is no slipping in the azimuthal plane. The fluid can be modeled as incompressible and subsonic in the axisymmetric plane. By treating the centrifuge as long, end effects can be appropriately modeled without performing a detailed boundary layer analysis. Onsager's pancake approximation is used to construct a simulation to model fluid flow in a gas centrifuge. The governing 6th order partial differential equation is broken down into an equivalent coupled system of three equations and then solved numerically. In addition to a discussion on the baseline solution, known problems and future work possibilities are presented.
TOUGH Simulations of the Updegraff's Set of Fluid and Heat Flow Problems
Moridis, G.J.; Pruess (editor), K.
The TOUGH code [Pruess, 1987] for two-phase flow of water, air, and heat in penneable media has been exercised on a suite of test problems originally selected and simulated by C. D. Updegraff [1989]. These include five 'verification' problems for which analytical or numerical solutions are available, and three 'validation' problems that model laboratory fluid and heat flow experiments. All problems could be run without any code modifications (*). Good and efficient numerical performance, as well as accurate results were obtained throughout. Additional code verification and validation problems from the literature are briefly summarized, and suggestions are given for proper applications of TOUGH and related codes.
Hydrostatic bearings for a turbine fluid flow metering device
Fincke, James R. (Rigby, ID)
A rotor assembly fluid metering device has been improved by development of a hydrostatic bearing fluid system which provides bearing fluid at a common pressure to rotor assembly bearing surfaces. The bearing fluid distribution system produces a uniform film of fluid between bearing surfaces and allows rapid replacement of bearing fluid between bearing surfaces, thereby minimizing bearing wear and corrosion.
Hydrostatic bearings for a turbine fluid flow metering device
Fincke, J.R.
A rotor assembly fluid metering device has been improved by development of a hydrostatic bearing fluid system which provides bearing fluid at a common pressure to rotor assembly bearing surfaces. The bearing fluid distribution system produces a uniform film of fluid between bearing surfaces and allows rapid replacement of bearing fluid between bearing surfaces, thereby minimizing bearing wear and corrosion. 3 figs.
Multiphase fluid flow and time lapse seismics UNLP, 11 Octubre de ...
Time-lapse seismic surveys aim to monitor the migration and dispersal of the CO2 plume after injection. Multiphase fluid flow and time lapse seismics � p. 3�...
Wave-induced fluid flow in random porous media: Attenuation and ...
wave attenuation and dispersion due to wave-induced fluid flow in 3-D randomly inhomogeneous .... tenuation is controlled by the integrand, that is, by the prod-.
Compressible fluid model for hydrodynamic lubrication cavitation
Sart, Remi
Compressible fluid model for hydrodynamic lubrication cavitation G. Bayada L. Chupin I.C.J. firstname.lastname@example.com Keywords: cavitation, compressible Reynolds equation Date: april 2013 Summary In this paper, it is shown how vaporous cavitation in lubricant films can be modelled in a physically justified manner through
Hydrostatic bearings for a turbine fluid flow metering device
Fincke, J.R.
A rotor assembly fluid metering device has been improved by development of a hydrostatic bearing fluid system which provides bearing fluid at a common pressure to rotor assembly bearing surfaces. The bearing fluid distribution system produces a uniform film of fluid distribution system produces a uniform film of fluid between bearing surfaces and allows rapid replacement of bearing fluid between bearing surfaces, thereby minimizing bearing wear and corrosion.
Scaling up and modeling for transport and flow
Rogina, Mladen
& modélisation des écoulements de fluides en milieux poreux DUBROVNIK, CROATIA 13-16 OCTOBER 2008 BOOK for Transport and Flow in Porous Media Dubrovnik, Croatia, 13-16 October 2008 Book of abstracts #12;Contents and Modeling for Transport and Flow in Porous Media, held at Dubrovnik, Croatia, 1316 October 2008
System and method for bidirectional flow and controlling fluid flow in a conduit
Ortiz, M.G.
A system for measuring bidirectional flow, including backflow, of fluid in a conduit is disclosed. The system utilizes a structural mechanism to create a pressure differential in the conduit. Pressure sensors are positioned upstream from the mechanism, at the mechanism, and downstream from the mechanism. Data from the pressure sensors are transmitted to a microprocessor or computer, and pressure differential detected between the pressure sensors is then used to calculate the backflow. Control signals may then be generated by the microprocessor or computer to shut off valves located in the conduit, upon the occurrence of backflow, or to control flow, total material dispersed, etc. in the conduit. 3 figs.
System and method for bidirectional flow and controlling fluid flow in a conduit
Ortiz, Marcos German (Idaho Falls, ID)
A system for measuring bidirectional flow, including backflow, of fluid in a conduit. The system utilizes a structural mechanism to create a pressure differential in the conduit. Pressure sensors are positioned upstream from the mechanism, at the mechanism, and downstream from the mechanism. Data from the pressure sensors are transmitted to a microprocessor or computer, and pressure differential detected between the pressure sensors is then used to calculate the backflow. Control signals may then be generated by the microprocessor or computer to shut off valves located in the conduit, upon the occurrence of backflow, or to control flow, total material dispersed, etc. in the conduit.
Pollard, David; Aydin, Atilla
Fractures and faults are brittle structural heterogeneities that can act both as conduits and barriers with respect to fluid flow in rock. This range in the hydraulic effects of fractures and faults greatly complicates the challenges faced by geoscientists working on important problems: from groundwater aquifer and hydrocarbon reservoir management, to subsurface contaminant fate and transport, to underground nuclear waste isolation, to the subsurface sequestration of CO2 produced during fossil-fuel combustion. The research performed under DOE grant DE-FG03-94ER14462 aimed to address these challenges by laying a solid foundation, based on detailed geological mapping, laboratory experiments, and physical process modeling, on which to build our interpretive and predictive capabilities regarding the structure, patterns, and fluid flow properties of fractures and faults in sandstone reservoirs. The material in this final technical report focuses on the period of the investigation from July 1, 2001 to October 31, 2004. The Aztec Sandstone at the Valley of Fire, Nevada, provides an unusually rich natural laboratory in which exposures of joints, shear deformation bands, compaction bands and faults at scales ranging from centimeters to kilometers can be studied in an analog for sandstone aquifers and reservoirs. The suite of structures there has been documented and studied in detail using a combination of low-altitude aerial photography, outcrop-scale mapping and advanced computational analysis. In addition, chemical alteration patterns indicative of multiple paleo fluid flow events have been mapped at outcrop, local and regional scales. The Valley of Fire region has experienced multiple episodes of fluid flow and this is readily evident in the vibrant patterns of chemical alteration from which the Valley of Fire derives its name. We have successfully integrated detailed field and petrographic observation and analysis, process-based mechanical modeling, and numerical simulation of fluid flow to study a typical sandstone aquifer/reservoir at a variety of scales. We have produced many tools and insights which can be applied to active subsurface flow systems and practical problems of pressing global importance.
Scaled Experimental Modeling of VHTR Plenum Flows
Abstract The Very High Temperature Reactor (VHTR) is the leading candidate for the Next Generation Nuclear Power (NGNP) Project in the U.S. which has the goal of demonstrating the production of emissions free electricity and hydrogen by 2015. Various scaled heated gas and water flow facilities were investigated for modeling VHTR upper and lower plenum flows during the decay heat portion of a pressurized conduction-cooldown scenario and for modeling thermal mixing and stratification (�thermal striping�) in the lower plenum during normal operation. It was concluded, based on phenomena scaling and instrumentation and other practical considerations, that a heated water flow scale model facility is preferable to a heated gas flow facility and to unheated facilities which use fluids with ranges of density to simulate the density effect of heating. For a heated water flow lower plenum model, both the Richardson numbers and Reynolds numbers may be approximately matched for conduction-cooldown natural circulation conditions. Thermal mixing during normal operation may be simulated but at lower, but still fully turbulent, Reynolds numbers than in the prototype. Natural circulation flows in the upper plenum may also be simulated in a separate heated water flow facility that uses the same plumbing as the lower plenum model. However, Reynolds number scaling distortions will occur at matching Richardson numbers due primarily to the necessity of using a reduced number of channels connected to the plenum than in the prototype (which has approximately 11,000 core channels connected to the upper plenum) in an otherwise geometrically scaled model. Experiments conducted in either or both facilities will meet the objectives of providing benchmark data for the validation of codes proposed for NGNP designs and safety studies, as well as providing a better understanding of the complex flow phenomena in the plenums.
Imaging Fluid Flow in Geothermal Wells Using Distributed Thermal Perturbation Sensing
Freifeld, B.; Finsterle, S.
The objective of Task 2 is to develop a numerical method for the efficient and accurate analysis of distributed thermal perturbation sensing (DTPS) data for (1) imaging flow profiles and (2) in situ determination of thermal conductivities and heat fluxes. Numerical forward and inverse modeling is employed to: (1) Examine heat and fluid flow processes near a geothermal well under heating and cooling conditions; (2) Demonstrate ability to interpret DTPS thermal profiles with acceptable estimation uncertainty using inverse modeling of synthetic temperature data; and (3) Develop template model and analysis procedure for the inversion of temperature data collected during a thermal perturbation test using fiber-optic distributed temperature sensors. This status report summarizes initial model developments and analyses.
DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 2
Not Available
The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the thermal sciences. The handbook includes information on thermodynamics and the properties of fluids; the three modes of heat transfer -- conduction, convection, and radiation; and fluid flow, and the energy relationships in fluid systems. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility fluid systems.
DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 1
Not Available
The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the thermal sciences. The handbook includes information on thermodynamics and the properties of fluids; the three modes of heat transfer -- conduction, convection, and radiation; and fluid flow, and the energy relationships in fluid systems. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility fluid systems.
DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 3
Not Available
The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the thermal sciences. The handbook includes information on thermodynamics and the properties of fluids; the three modes of heat transfer -- conduction, convection, and radiation; and fluid flow, and the energy relationships in fluid systems. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility fluid systems.
Device and method for measuring fluid flow in a conduit having a gradual bend
Ortiz, M.G.; Boucher, T.J.
A system is described for measuring fluid flow in a conduit having a gradual bend or arc, and a straight section. The system includes pressure transducers, one or more disposed in the conduit on the outside of the arc, and one disposed in the conduit in a straight section thereof. The pressure transducers measure the pressure of fluid in the conduit at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the conduit. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the conduit elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow. 1 fig.
Numerical Simulation of the Flow of a Power Law Fluid in an Elbow Bend
Kanakamedala, Karthik
A numerical study of flow of power law fluid in an elbow bend has been carried out. The motivation behind this study is to analyze the velocity profiles, especially the pattern of the secondary flow of power law fluid in a bend as there are several...
Estimating maximum sustainable injection pressure during geological sequestration of CO2 using coupled fluid flow and
Vall�e, Martin
coupled fluid flow and geomechanical fault-slip analysis J. Rutqvist *, J. Birkholzer, F. Cappa, C demonstrates the use of coupled fluid flow and geomechanical fault slip (fault reactivation) analysis: Geological CO2 sequestration; geomechanics; Fault slip; Stress; Caprock integrity; CO2 injection 1
Global weak solutions to magnetic fluid flows with nonlinear Maxwell-Cattaneo heat transfer law
Boyer, Edmond
Global weak solutions to magnetic fluid flows with nonlinear Maxwell-Cattaneo heat transfer law F transfer in a magnetic fluid flow under the action of an applied magnetic field. Instead of the usual heat-Cattaneo law, heat transfer, magnetic field, magnetization AMS subject classifications: 76N10, 35Q35. 1
Mutiscale Modeling of Segregation in Granular Flows
Jin Sun
Modeling and simulation of segregation phenomena in granular flows are investigated. Computational models at different scales ranging from particle level (microscale) to continuum level (macroscale) are employed in order to determine the important microscale physics relevant to macroscale modeling. The capability of a multi-fluid model to capture segregation caused by density difference is demonstrated by simulating grain-chaff biomass flows in a laboratory-scale air column and in a combine harvester. The multi-fluid model treats gas and solid phases as interpenetrating continua in an Eulerian frame. This model is further improved by incorporating particle rotation using kinetic theory for rapid granular flow of slightly frictional spheres. A simplified model is implemented without changing the current kinetic theory framework by introducing an effective coefficient of restitution to account for additional energy dissipation due to frictional collisions. The accuracy of predicting segregation rate in a gas-fluidized bed is improved by the implementation. This result indicates that particle rotation is important microscopic physics to be incorporated into the hydrodynamic model. Segregation of a large particle in a dense granular bed of small particles under vertical. vibration is studied using molecular dynamics simulations. Wall friction is identified as a necessary condition for the segregation. Large-scale force networks bearing larger-than-average forces are found with the presence of wall friction. The role of force networks in assisting rising of the large particle is analyzed. Single-point force distribution and two-point spatial force correlation are computed. The results show the heterogeneity of forces and a short-range correlation. The short correlation length implies that even dense granular flows may admit local constitutive relations. A modified minimum spanning tree (MST) algorithm is developed to asymptotically recover the force statistics in the force networks. This algorithm provides a possible route to constructing a continuum model with microstructural information supplied from it. Microstructures in gas fluidized beds are also analyzed using a hybrid method, which couples the discrete element method (DEM) for particle dynamics with the averaged two-fluid (TF) equations for the gas phase. Multi-particle contacts are found in defluidized regions away from bubbles in fluidized beds. The multi-particle contacts invalidate the binary-collision assumption made in the kinetic theory of granular flows for the defluidized regions. Large ratios of contact forces to drag forces are found in the same regions, which confirms the relative importance of contact forces in determining particle dynamics in the defluidized regions.
Characterization and fluid flow simulation of naturally fractured Frontier sandstone, Green River Basin, Wyoming
Harstad, H. [New Mexico Tech, Socorro, NM (United States); Teufel, L.W.; Lorenz, J.C.; Brown, S.R. [Sandia National Labs., Albuquerque, NM (United States). Geomechanics Dept.
Significant gas reserves are present in low-permeability sandstones of the Frontier Formation in the greater Green River Basin, Wyoming. Successful exploitation of these reservoirs requires an understanding of the characteristics and fluid-flow response of the regional natural fracture system that controls reservoir productivity. Fracture characteristics were obtained from outcrop studies of Frontier sandstones at locations in the basin. The fracture data were combined with matrix permeability data to compute an anisotropic horizontal permeability tensor (magnitude and direction) corresponding to an equivalent reservoir system in the subsurface using a computational model developed by Oda (1985). This analysis shows that the maximum and minimum horizontal permeability and flow capacity are controlled by fracture intensity and decrease with increasing bed thickness. However, storage capacity is controlled by matrix porosity and increases linearly with increasing bed thickness. The relationship between bed thickness and the calculated fluid-flow properties was used in a reservoir simulation study of vertical, hydraulically-fractured and horizontal wells and horizontal wells of different lengths in analogous naturally fractured gas reservoirs. The simulation results show that flow capacity dominates early time production, while storage capacity dominates pressure support over time for vertical wells. For horizontal wells drilled perpendicular to the maximum permeability direction a high target production rate can be maintained over a longer time and have higher cumulative production than vertical wells. Longer horizontal wells are required for the same cumulative production with decreasing bed thickness.
Computational fluid dynamic modeling of fluidized-bed polymerization reactors
Rokkam, Ram [Ames Laboratory
Polyethylene is one of the most widely used plastics, and over 60 million tons are produced worldwide every year. Polyethylene is obtained by the catalytic polymerization of ethylene in gas and liquid phase reactors. The gas phase processes are more advantageous, and use fluidized-bed reactors for production of polyethylene. Since they operate so close to the melting point of the polymer, agglomeration is an operational concern in all slurry and gas polymerization processes. Electrostatics and hot spot formation are the main factors that contribute to agglomeration in gas-phase processes. Electrostatic charges in gas phase polymerization fluidized bed reactors are known to influence the bed hydrodynamics, particle elutriation, bubble size, bubble shape etc. Accumulation of electrostatic charges in the fluidized-bed can lead to operational issues. In this work a first-principles electrostatic model is developed and coupled with a multi-fluid computational fluid dynamic (CFD) model to understand the effect of electrostatics on the dynamics of a fluidized-bed. The multi-fluid CFD model for gas-particle flow is based on the kinetic theory of granular flows closures. The electrostatic model is developed based on a fixed, size-dependent charge for each type of particle (catalyst, polymer, polymer fines) phase. The combined CFD model is first verified using simple test cases, validated with experiments and applied to a pilot-scale polymerization fluidized-bed reactor. The CFD model reproduced qualitative trends in particle segregation and entrainment due to electrostatic charges observed in experiments. For the scale up of fluidized bed reactor, filtered models are developed and implemented on pilot scale reactor.
Integrated Nozzle Flow, Spray, Combustion, & Emission Modeling...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Nozzle Flow, Spray, Combustion, & Emission Modeling using KH-ACT Primary Breakup Model & Detailed Chemistry Integrated Nozzle Flow, Spray, Combustion, & Emission Modeling using...
Magnetic fluid flow phenomena in DC and rotating magnetic fields
Rhodes, Scott E. (Scott Edward), 1981-
An investigation of magnetic fluid experiments and analysis is presented in three parts: a study of magnetic field induced torques in magnetorheological fluids, a characterization and quantitative measurement of properties ...
Time-lapse seismic monitoring of subsurface fluid flow
Yuh, Sung H.
Time-lapse seismic monitoring repeats 3D seismic imaging over a reservoir to map fluid movements in a reservoir. During hydrocarbon production, the fluid saturation, pressure, and temperature of a reservoir change, thereby altering the acoustic...
Modeling Traffic Flow Emissions
Cappiello, Alessandra
The main topic of this thesis is the development of light-duty vehicle dynamic emission models and their integration with dynamic traffic models. Combined, these models
A simple segregated flow model for a WAG process
Hopkins, Christopher Wright
integration, a volumetric balance of the injectants and the initial reservoir fluids is obtained. The model was developed with several simplifying assumptions including immiscible water and gas phases, incompressible fluid f'low, no trapped oil volumes... with the process are the relatively higher sweep efficiencies of water floods and the low residual oil saturations of miscible gas injection. The mechanism oP water flooding is generally well understood. Many Pields have been and still are being waterflooded...
2.13 HEAT TRANSFER & FLUID FLOW IN MICROCHANNELS 2.13.7-1 Molecular dynamics methods in
Maruyama, Shigeo
2.13 HEAT TRANSFER & FLUID FLOW IN MICROCHANNELS 2.13.7-1 2.13.7 Molecular dynamics methods in microscale heat transfer Shigeo Maruyama A. Introduction In normal heat transfer and fluid flow calculations of molecules. This situation is approached in microscale heat transfer and fluid flow. Molecular level
Multiphase Fluid Flow in Deformable Variable-Aperture Fractures - Final Report
Detwiler, Russell
Fractures provide flow paths that can potentially lead to fast migration of fluids or contaminants. A number of energy-�?related applications involve fluid injections that significantly perturb both the pressures and chemical composition of subsurface fluids. These perturbations can cause both mechanical deformation and chemical alteration of host rocks with potential for significant changes in permeability. In fractured rock subjected to coupled chemical and mechanical stresses, it can be difficult to predict the sign of permeability changes, let alone the magnitude. This project integrated experimental and computational studies to improve mechanistic understanding of these coupled processes and develop and test predictive models and monitoring techniques. The project involved three major components: (1) study of two-�?phase flow processes involving mass transfer between phases and dissolution of minerals along fracture surfaces (Detwiler et al., 2009; Detwiler, 2010); (2) study of fracture dissolution in fractures subjected to normal stresses using experimental techniques (Ameli, et al., 2013; Elkhoury et al., 2013; Elkhoury et al., 2014) and newly developed computational models (Ameli, et al., 2014); (3) evaluation of electrical resistivity tomography (ERT) as a method to detect and quantify gas leakage through a fractured caprock (Breen et al., 2012; Lochbuhler et al., 2014). The project provided support for one PhD student (Dr. Pasha Ameli; 2009-�?2013) and partially supported a post-�?doctoral scholar (Dr. Jean Elkhoury; 2010-�?2013). In addition, the project provided supplemental funding to support collaboration with Dr. Charles Carrigan at Lawrence Livermore National Laboratory in connection with (3) and supported one MS student (Stephen Breen; 2011-�?2013). Major results from each component of the project include the following: (1) Mineral dissolution in fractures occupied by two fluid phases (e.g., oil-�?water or water-�?CO{sub 2}) causes changes in local capillary forces and redistribution of fluids. These coupled processes enhance channel formation and the potential for development of fast flow paths through fractures. (2) Dissolution in fractures subjected to normal stress can result in behaviors ranging from development of dissolution channels and rapid permeability increases to fracture healing and significant permeability decreases. The timescales associated with advective transport of dissolved ions in the fracture, mineral dissolution rates, and diffusion within the adjacent porous matrix dictate the sign and magnitude of the resulting permeability changes. Furthermore, a high-�? resolution mechanistic model that couples elastic deformation of contacts and aperture-�?dependent dissolution rates predicts the range of observed behaviors reasonably well. (3) ERT has potential as a tool for monitoring gas leakage in deep formations. Using probabilistic inversion methods further enhances the results by providing uncertainty estimates of inverted parameters.
Method and apparatus for measuring the mass flow rate of a fluid
Evans, Robert P. (Idaho Falls, ID); Wilkins, S. Curtis (Idaho Falls, ID); Goodrich, Lorenzo D. (Shelley, ID); Blotter, Jonathan D. (Pocatello, ID)
A non invasive method and apparatus is provided to measure the mass flow rate of a multi-phase fluid. An accelerometer is attached to a pipe carrying a multi-phase fluid. Flow related measurements in pipes are sensitive to random velocity fluctuations whose magnitude is proportional to the mean mass flow rate. An analysis of the signal produced by the accelerometer shows a relationship between the mass flow of a fluid and the noise component of the signal of an accelerometer. The noise signal, as defined by the standard deviation of the accelerometer signal allows the method and apparatus of the present invention to non-intrusively measure the mass flow rate of a multi-phase fluid.
Multiscale modeling in granular flow
Rycroft, Christopher Harley
Granular materials are common in everyday experience, but have long-resisted a complete theoretical description. Here, we consider the regime of slow, dense granular flow, for which there is no general model, representing ...
A nonlocal model for fluid-structure interaction with applications in hydraulic fracturing
Turner, Daniel Z
Modeling important engineering problems related to flow-induced damage (in the context of hydraulic fracturing among others) depends critically on characterizing the interaction of porous media and interstitial fluid flow. This work presents a new formulation for incorporating the effects of pore pressure in a nonlocal representation of solid mechanics. The result is a framework for modeling fluid-structure interaction problems with the discontinuity capturing advantages of an integral based formulation. A number of numerical examples are used to show that the proposed formulation can be applied to measure the effect of leak-off during hydraulic fracturing as well as modeling consolidation of fluid saturated rock and surface subsidence caused by fluid extraction from a geologic reservoir. The formulation incorporates the effect of pore pressure in the constitutive description of the porous material in a way that is appropriate for nonlinear materials, easily implemented in existing codes, straightforward in i...
Multiscale Simulation Framework for Coupled Fluid Flow and Mechanical Deformation
Tchelepi, Hamdi
A multiscale linear-solver framework for the pressure equation associated with flow in highly heterogeneous porous formations was developed. The multiscale based approach is cast in a general algebraic form, which facilitates integration of the new scalable linear solver in existing flow simulators. The Algebraic Multiscale Solver (AMS) is employed as a preconditioner within a multi-stage strategy. The formulations investigated include the standard MultiScale Finite-Element (MSFE) andMultiScale Finite-Volume (MSFV) methods. The local-stage solvers include incomplete factorization and the so-called Correction Functions (CF) associated with the MSFV approach. Extensive testing of AMS, as an iterative linear solver, indicate excellent convergence rates and computational scalability. AMS compares favorably with advanced Algebraic MultiGrid (AMG) solvers for highly detailed three-dimensional heterogeneous models. Moreover, AMS is expected to be especially beneficial in solving time-dependent problems of coupled multiphase flow and transport in large-scale subsurface formations.
The stability of viscoelastic fluids in complex flows : the role of shear and extensional rheology
Rothstein, Jonathan P. (Jonathan Philip), 1974-
Understanding the flow of polymeric fluids is important for optimizing commercial processes such as injection molding and fiber spinning. The combination of streamwise curvature and elastic normal stresses can lead to the ...
IN THE COSO GEOTHERMAL FIELD Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Proceedings: IN SITU STRESS, FRACTURE, AND FLUID FLOW ANALYSIS IN WELL...
OF THE COSO GEOTHERMAL FIELD Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Proceedings: IN SITU STRESS, FRACTURE AND FLUID FLOW ANALYSIS-EAST...
Permeability of illite-bearing shale: 2. Influence of fluid chemistry on flow and functionally
Herbert, Bruce
Permeability of illite-bearing shale: 2. Influence of fluid chemistry on flow and functionally; accepted 14 July 2004; published 14 October 2004. [1] Bedding-parallel permeability of illite-rich shale Geochemistry: Low-temperature geochemistry; KEYWORDS: permeability, shale, fluid chemistry Citation: Kwon, O
Cartesian Cut Cell Two-Fluid Solver for Hydraulic Flow Problems
Ingram, David
Cartesian Cut Cell Two-Fluid Solver for Hydraulic Flow Problems L. Qian1 ; D. M. Causon2 ; D. M. Ingram3 ; and C. G. Mingham4 Abstract: A two-fluid solver which can be applied to a variety of hydraulic with a sloping beach is also calculated to demonstrate the applicability of the method to real hydraulic problems
Fluid Flow and Infiltration in Structured Fibrous Porous Media
Papathanasiou, Thanasis D.
Present the results of an extensive computational investigation of flow through structured fibrous media.
An overview of instability and fingering during immiscible fluid flow in porous and fractured media
Chen, G.; Neuman, S.P. [Univ. of Arizona, Tucson, AZ (United States). Dept. of Hydrology and Water Resources; Taniguchi, M. [Nara Univ. of Education (Japan). Dept. of Earth Sciences
Wetting front instability is an important phenomenon affecting fluid flow and contaminant transport in unsaturated soils and rocks. It causes the development of fingers which travel faster than would a uniform front and thus bypass much of the medium. Water saturation and solute concentration in such fingers tend to be higher than in the surrounding medium. During infiltration, fingering may cause unexpectedly rapid arrival of water and solute at the water-table. This notwithstanding, most models of subsurface flow and transport ignore instability and fingering. In this report, we survey the literature to assess the extent to which this may or may not be justified. Our overview covers experiments, theoretical studies, and computer simulations of instability and fingering during immiscible two-phase flow and transport, with emphasis on infiltration into soils and fractured rocks. Our description of instability in an ideal fracture (Hele-Shaw cell) includes an extension of existing theory to fractures and interfaces having arbitrary orientations in space. Our discussion of instability in porous media includes a slight but important correction of existing theory for the case of an inclined interface. We conclude by outlining some potential directions for future research. Among these, we single out the effect of soil and rock heterogeneities on instability and preferential flow as meriting special attention in the context of nuclear waste storage in unsaturated media.
Multiphase flow and control of fluid path in microsystems
Jhunjhunwala, Manish
Miniaturized chemical-systems are expected to have advantages of handling, portability, cost, speed, reproducibility and safety. Control of fluid path in small channels between processes in a chemical/biological network ...
Device and method for measuring multi-phase fluid flow and density of fluid in a conduit having a gradual bend
Ortiz, M.G.; Boucher, T.J.
A system is described for measuring fluid flow in a conduit having a gradual bend or arc, and a straight section. The system includes pressure transducers, one or more disposed in the conduit on the outside of the arc, and one disposed in the conduit in a straight section thereof. The pressure transducers measure the pressure of fluid in the conduit at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the conduit. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the conduit elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow. 1 fig.
Flow and heat transfer of a third grade fluid past an exponentially stretching sheet with
Paris-Sud XI, Universit� de
Flow and heat transfer of a third grade fluid past an exponentially stretching sheet with partial-Newtonian boundary layer flow and heat transfer over an exponentially stretch- ing sheet with partial slip boundary. The heat transfer analysis has been carried out for two heating processes, namely (i) with prescribed sur
FRACSTIM/I: A Fully Coupled Fluid Flow/Heat Transport and Geomechanica...
Broader source: Energy.gov (indexed) [DOE]
Using Solid Particles as Heat Transfer Fluid for use in Concentrating Solar Power (CSP) Plants Coupled Thermal-Hydrological-Mechanical-Chemical Model And Experiments For...
Standardization of Thermo-Fluid Modeling in Modelica.Fluid
Franke, Rudiger
a replaceable heat transfer model with the flag use_heat transfer. A concrete heat transfer model extending fromcycle. Also note that the heat transfer model of the tank is
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the YouTube|6721 Federal Register / Vol. 73,H Model SeniorDepartment ofInfographicEIAEIN
Numerical simulation of the non-isothermal developing flow of a nonlinear viscoelastic fluid in a rectangular channel
Nikoleris, Teo
Fluid in a Rectangular Channel (December 1988) Teo Nikoleris, B. S. , Reed College Chairman of Advisory Committee: Dr. R. Darby An orthogonal collocation finite element program was used to numerically model the hydrodynamicslly and thermally... in negligible increase of Nw~ ~?. Also, the approach of Chang and Finlayson [6], [7] who applied orthogonal collocation finite elements in conjunction with bicubic Hermitian polynomials to approximate various viscoelastic flow problems, also met with little...
Modelling of multiphase flow in ironmaking blast furnace
Dong, X.F.; Yu, A.B.; Burgess, J.M.; Pinson, D.; Chew, S.; Zulli, P. [University of New South Wales, Sydney, NSW (Australia). School for Material Science and Engineering
A mathematical model for the four-phase (gas, powder, liquid, and solids) flow in a two-dimensional ironmaking blast furnace is presented by extending the existing two-fluid flow models. The model describes the motion of gas, solid, and powder phases, based on the continuum approach, and implements the so-called force balance model for the flow of liquids, such as metal and slag in a blast furnace. The model results demonstrate a solid stagnant zone and dense powder hold-up region, as well as a dense liquid flow region that exists in the lower part of a blast furnace, which are consistent with the experimental observations reported in the literature. The simulation is extended to investigate the effects of packing properties and operational conditions on the flow and the volume fraction distribution of each phase in a blast furnace. It is found that solid movement has a significant effect on powder holdup distribution. Small solid particles and low porosity distribution are predicted to affect the fluid flow considerably, and this can cause deterioration in bed permeability. The dynamic powder holdup in a furnace increases significantly with the increase of powder diameter. The findings should be useful to better understand and control blast furnace operations.
Mass-Conserved Phase Field Models for Binary Fluids
The commonly used incompressible phase field models for non-reactive, bi- nary fluids, in which the Cahn-Hilliard equation is used for the transport of phase.
Message Flow Modeling Oscar Nierstrasz
Nierstrasz, Oscar
Message Flow Modeling Oscar Nierstrasz and Dennis Tsichritzis Computer Systems Research Group University of Toronto ABSTRACT A message management system provides users with a facility for automatically handling messages. This paper describes a technique for characterizing the behaviour of such a system
Documenting Organizational Process Flow Modeling
Schweik, Charles M.
1 Documenting Organizational Processes or Process Flow Modeling Analysis Phase � Three Steps that describes (1) the current, and (2) the future structure of an organizational process �"Natural language � An overview of an organizational system showing � system boundaries, � external entities that interact
Fluid and heat flow in gas-rich geothermal reservoirs
O'Sullivan, M.J.; Bodvarsson, G.S.; Pruess, K.; Blakeley, M.R.
Numerical-simulation techniques are used to study the effects of noncondensible gases (CO/sub 2/) on geothermal reservoir behavior in the natural state and during exploitation. It is shown that the presence of CO/sub 2/ has large effects on the thermodynamic conditions of a reservoir in the natural state, especially on temperature distributions and phase compositions. The gas will expand two-phase zones and increase gas saturations to enable flow of CO/sub 2/ through the system. During exploitation, the early pressure drop is primarily due to degassing of the system. This process can cause a very rapid initial pressure drop, on the order of tens of bars, depending upon the initial partial pressure of CO/sub 2/. The following gas content from wells can provide information on in-place gas saturations and relative permeability curves that apply at a given geothermal resource. Site-specific studies are made for the gas-rich two-phase reservoir at the Ohaki geothermal field in New Zealand. A simple lumped-parameter model and a vertical column model are applied to the field data. The results obtained agree well with the natural thermodynamic state of the Ohaki field (pressure and temperature profiles) and a partial pressure of 15 to 25 bars is calculated in the primary reservoirs. The models also agree reasonably well with field data obtained during exploitation of the field. The treatment of thermophysical properties of H/sub 2/O-CO/sub 2/ mixtures for different phase compositions is summarized.
Role of viscoelasticity and non-linear rheology in flows of complex fluids at high deformation rates
Ober, Thomas J. (Thomas Joseph)
We combine pressure, velocimetry and birefringence measurements to study three phenomena for which the fluid rheology plays a dominant role: 1) shear banding in micellar fluids, 2) extension-dominated flows in microfluidic ...
Calculation of unsteady turbulent flow around obstacles using the large eddy simulation turbulence model
Helton, Donald McLean
The premise of the work presented here is to use a common analytical tool, Computational Fluid Dynamics (CFD), along with a prevalent turbulence model, Large Eddy Simulation (LES), to study the flow past rectangular cylinders. In an attempt to use...
Dispersed Fluid Flow in Fractured Reservoirs- an Analysis of...
Distributions Abstract A methodology for analyzing the internal flow characteristics of a fractured geothermal reservoir using tracer-determined residence time distribution curves...
Nonlinear evolution of the magnetized Kelvin-Helmholtz instability: From fluid to kinetic modeling
Henri, P. [Dipartimento di Fisica, Universit� di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy) [Dipartimento di Fisica, Universit� di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy); Universit� de Nice Sophia Antipolis, CNRS, Observatoire de la C�te d'Azur, BP 4229 06304, Nice Cedex 4 (France); Cerri, S. S. [Dipartimento di Fisica, Universit� di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy) [Dipartimento di Fisica, Universit� di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy); Max-Planck-Institut f�r Plasmaphysik, EURATOM Association, D-85748 Garching (Germany); Califano, F.; Pegoraro, F. [Dipartimento di Fisica, Universit� di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy)] [Dipartimento di Fisica, Universit� di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy); Rossi, C. [Dipartimento di Fisica, Universit� di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy) [Dipartimento di Fisica, Universit� di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy); LPP-CNRS, Ecole Polytechnique, UPMC, Universit� Paris VI, Universit� Paris XI, route de Saclay, 91128 Palaiseau (France); Faganello, M. [International Institute for Fusion Science/PIIM, UMR 7345 CNRS, Aix-Marseille University, 13397 Marseille (France)] [International Institute for Fusion Science/PIIM, UMR 7345 CNRS, Aix-Marseille University, 13397 Marseille (France); �ebek, O. [Astronomical Institute and Institute of Atmospheric Physics, AS CR Bocni II/1401, CZ-14131 Prague, Czech Republic and Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, B?ehov� 7, 11519 Prague (Czech Republic)] [Astronomical Institute and Institute of Atmospheric Physics, AS CR Bocni II/1401, CZ-14131 Prague, Czech Republic and Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, B?ehov� 7, 11519 Prague (Czech Republic); Tr�vn�?ek, P. M. [Space Sciences Laboratory, University of California Berkeley, 7 Gauss Way, Berkeley, California 94720, USA and Astronomical Institute and Institute of Atmospheric Physics, AS CR Bocni II/1401, CZ-14131 Prague (Czech Republic)] [Space Sciences Laboratory, University of California Berkeley, 7 Gauss Way, Berkeley, California 94720, USA and Astronomical Institute and Institute of Atmospheric Physics, AS CR Bocni II/1401, CZ-14131 Prague (Czech Republic); Hellinger, P. [Astronomical Institute and Institute of Atmospheric Physics, AS CR Bocni II/1401, CZ-14131 Prague (Czech Republic)] [Astronomical Institute and Institute of Atmospheric Physics, AS CR Bocni II/1401, CZ-14131 Prague (Czech Republic); and others
The nonlinear evolution of collisionless plasmas is typically a multi-scale process, where the energy is injected at large, fluid scales and dissipated at small, kinetic scales. Accurately modelling the global evolution requires to take into account the main micro-scale physical processes of interest. This is why comparison of different plasma models is today an imperative task aiming at understanding cross-scale processes in plasmas. We report here the first comparative study of the evolution of a magnetized shear flow, through a variety of different plasma models by using magnetohydrodynamic (MHD), Hall-MHD, two-fluid, hybrid kinetic, and full kinetic codes. Kinetic relaxation effects are discussed to emphasize the need for kinetic equilibriums to study the dynamics of collisionless plasmas in non trivial configurations. Discrepancies between models are studied both in the linear and in the nonlinear regime of the magnetized Kelvin-Helmholtz instability, to highlight the effects of small scale processes on the nonlinear evolution of collisionless plasmas. We illustrate how the evolution of a magnetized shear flow depends on the relative orientation of the fluid vorticity with respect to the magnetic field direction during the linear evolution when kinetic effects are taken into account. Even if we found that small scale processes differ between the different models, we show that the feedback from small, kinetic scales to large, fluid scales is negligible in the nonlinear regime. This study shows that the kinetic modeling validates the use of a fluid approach at large scales, which encourages the development and use of fluid codes to study the nonlinear evolution of magnetized fluid flows, even in the collisionless regime.
Ice Shelves as Floating Channel Flows of Viscous Power-Law Fluids
Banik, Indranil
We attempt to better understand the flow of marine ice sheets. Treating ice as a viscous shear-thinning power law fluid, we develop an asymptotic (late-time) theory in two cases - the presence or absence of contact with sidewalls. Most real-world situations fall somewhere between the two extreme cases considered. When sidewalls are absent, we obtain the equilibrium grounding line thickness using a simple computer model and have an analytic approximation. For shelves in contact with sidewalls, we obtain an asymptotic theory, valid for long shelves. Our theory is based on the velocity profile across the channel being a generalised version of Poiseuille flow, which works when lateral shear dominates the force balance. We determine when this is. We conducted experiments using a laboratory model for ice. This was a suspension of xanthan in water, at a concentration of 0.5% by mass. The lab model has $n \\approx 3.8$ (similar to that of ice). The experiments agreed extremely well with our theories for all relevant p...
U-Sr isotopic speedometer: Fluid flow and chemical weatheringrates inaquifers
Maher, Kate; DePaolo, Donald J.; Christensen, John N.
Both chemical weathering rates and fluid flow are difficultto measure in natural systems. However, these parameters are critical forunderstanding the hydrochemical evolution of aquifers, predicting thefate and transport of contaminants, and for water resources/water qualityconsiderations. 87Sr/86Sr and (234U/238U) activity ratios are sensitiveindicators of water-rock interaction, and thus provide a means ofquantifying both flow and reactivity. The 87Sr/86Sr values in groundwaters are controlled by the ratio of the dissolution rate to the flowrate. Similarly, the (234U/238U) ratio of natural ground waters is abalance between the flow rate and the dissolution of solids, andalpha-recoil loss of 234U from the solids. By coupling these two isotopesystems it is possible to constrain both the long-term (ca. 100's to1000's of years) flow rate and bulk dissolution rate along the flow path.Previous estimates of the ratio of the dissolution rate to theinfiltration flux from Sr isotopes (87Sr/86Sr) are combined with a modelfor (234U/238U) to constrain the infiltration flux and dissolution ratefor a 70-m deep vadose zone core from Hanford, Washington. The coupledmodel for both (234U/238U) ratios and the 87Sr/86Sr data suggests aninfiltration flux of 5+-2 mm/yr, and bulk silicate dissolution ratesbetween 10-15.7 and 10-16.5 mol/m2/s. The process of alpha-recoilenrichment, while primarily responsible for the observed variation in(234U/238U) of natural systems, is difficult to quantify. However, therate of this process in natural systems affects the interpretation ofmost U-series data. Models for quantifying the alpha-recoil loss fractionbased on geometric predictions, surface area constraints, and chemicalmethods are also presented. The agreement between the chemical andtheoretical methods, such as direct measurement of (234U/238U) of thesmall grain size fraction and geometric calculations for that sizefraction, is quite good.
Preliminary studies of coolant by-pass flows in a prismatic very high temperature reactor using computational fluid dynamics
Hiroyuki Sato; Richard Johnson; Richard Schultz
Three dimensional computational fluid dynamic (CFD) calculations of a typical prismatic very high temperature gas-cooled reactor (VHTR) were conducted to investigate the influence of gap geometry on flow and temperature distributions in the reactor core using commercial CFD code FLUENT. Parametric calculations changing the gap width in a whole core length model of fuel and reflector columns were performed. The simulations show the effects of core by-pass flows in the heated core region by comparing results for several gap widths including zero gap width. The calculation results underline the importance of considering inter-column gap width for the evaluation of maximum fuel temperatures and temperature gradients in fuel blocks. In addition, it is shown that temperatures of core outlet flow from gaps and channels are strongly affected by the gap width of by-pass flow in the reactor core.
Stochastic models for turbulent reacting flows
Kerstein, A. [Sandia National Laboratories, Livermore, CA (United States)
The goal of this program is to develop and apply stochastic models of various processes occurring within turbulent reacting flows in order to identify the fundamental mechanisms governing these flows, to support experimental studies of these flows, and to further the development of comprehensive turbulent reacting flow models.
Thermodynamic Micellization Model of Asphaltene Precipitation from Petroleum Fluids
Firoozabadi, Abbas
Thermodynamic Micellization Model of Asphaltene Precipitation from Petroleum Fluids Alexey I A thermodynamicmicellization model is proposed for the description of asphaltene precipitationfrom petroleum fluids and the onset of predicted asphaltene precipitation are sensitive to the amount of resins in the crude
Title of dissertation: MODELING, SIMULATING, AND CONTROLLING THE FLUID DYNAMICS
Shapiro, Benjamin
ABSTRACT Title of dissertation: MODELING, SIMULATING, AND CONTROLLING THE FLUID DYNAMICS OF ELECTRO an algorithm to steer indi- vidual particles inside the EWOD system by control of actuators already present number of actuators available in the EWOD system. #12;MODELING, SIMULATING, AND CONTROLLING THE FLUID
Production of Natural Gas and Fluid Flow in Tight Sand Reservoirs
Maria Cecilia Bravo; Mariano Gurfinkel
This document reports progress of this research effort in identifying possible relationships and defining dependencies between macroscopic reservoir parameters strongly affected by microscopic flow dynamics and production well performance in tight gas sand reservoirs. Based on a critical review of the available literature, a better understanding of the main weaknesses of the current state of the art of modeling and simulation for tight sand reservoirs has been reached. Progress has been made in the development and implementation of a simple reservoir simulator that is still able to overcome some of the deficiencies detected. The simulator will be used to quantify the impact of microscopic phenomena in the macroscopic behavior of tight sand gas reservoirs. Phenomena such as, Knudsen diffusion, electro-kinetic effects, ordinary diffusion mechanisms and water vaporization are being considered as part of this study. To date, the adequate modeling of gas slippage in porous media has been determined to be of great relevance in order to explain unexpected fluid flow behavior in tight sand reservoirs.
Porosity, Permeability, And Fluid Flow In The Yellowstone Geothermal...
section of the 0.6-Ma Lava Creek ash-flow tuff. In this core, the degree of welding appears to be responsible for most of the variations in porosity, matrix...
NMRI methods for characterizing fluid flow in porous media
Yao, Xiaoli
in the measurement and the prediction of flow permeability in rocks. We have investigated the application of Nuclear Magnetic Resonance Imaging to velocity measurement. A stimulated echo pulse field gradient approach was proposed to measure the localized velocity...
Numerical simulation of flow separation control by oscillatory fluid injection�
Resendiz Rosas, Celerino
In this work, numerical simulations of flow separation control are performed. The sep-aration control technique studied is called 'synthetic jet actuation'. The developed code employs a cell centered finite volume scheme which handles viscous...
Multiscale modeling for fluid transport in nanosystems.
Lee, Jonathan W.; Jones, Reese E.; Mandadapu, Kranthi Kiran; Templeton, Jeremy Alan; Zimmerman, Jonathan A.
Atomistic-scale behavior drives performance in many micro- and nano-fluidic systems, such as mircrofludic mixers and electrical energy storage devices. Bringing this information into the traditionally continuum models used for engineering analysis has proved challenging. This work describes one such approach to address this issue by developing atomistic-to-continuum multi scale and multi physics methods to enable molecular dynamics (MD) representations of atoms to incorporated into continuum simulations. Coupling is achieved by imposing constraints based on fluxes of conserved quantities between the two regions described by one of these models. The impact of electric fields and surface charges are also critical, hence, methodologies to extend finite-element (FE) MD electric field solvers have been derived to account for these effects. Finally, the continuum description can have inconsistencies with the coarse-grained MD dynamics, so FE equations based on MD statistics were derived to facilitate the multi scale coupling. Examples are shown relevant to nanofluidic systems, such as pore flow, Couette flow, and electric double layer.
Magnetohydrodynamic pump with a system for promoting flow of fluid in one direction
Lemoff, Asuncion V. (Union City, CA); Lee, Abraham P. (Irvine, CA)
A magnetohydrodynamic pump for pumping a fluid. The pump includes a microfluidic channel for channeling the fluid, a MHD electrode/magnet system operatively connected to the microfluidic channel, and a system for promoting flow of the fluid in one direction in the microfluidic channel. The pump has uses in the medical and biotechnology industries for blood-cell-separation equipment, biochemical assays, chemical synthesis, genetic analysis, drug screening, an array of antigen-antibody reactions, combinatorial chemistry, drug testing, medical and biological diagnostics, and combinatorial chemistry. The pump also has uses in electrochromatography, surface micromachining, laser ablation, inkjet printers, and mechanical micromilling.
Microgravity Flow Regime Transition Modeling
Shephard, Adam M.
by Ghrist (2008) where an existing computer code, RELAP 5-3D, demonstrated the limitations of currently available computational modeling when applied to zero-g conditions. 1.2.2 EXPERIMENTAL APPARATUS All flow regime mapping experiments consist of a... ............................................................... 9 2.3 Dukler et al. 1988/Janicot 1988 ............................................. 9 2.4 Colin et al. 1991 .................................................................... 11 2.5 Huckerby and Rezkallah 1992...
Method and apparatus for simultaneous determination of fluid mass flow rate, mean velocity and density
Hamel, William R. (Farragut, TN)
This invention relates to a new method and new apparatus for determining fluid mass flowrate and density. In one aspect of the invention, the fluid is passed through a straight cantilevered tube in which transient oscillation has been induced, thus generating Coriolis damping forces on the tube. The decay rate and frequency of the resulting damped oscillation are measured, and the fluid mass flowrate and density are determined therefrom. In another aspect of the invention, the fluid is passed through the cantilevered tube while an electrically powered device imparts steady-state harmonic excitation to the tube. This generates Coriolis tube-damping forces which are dependent on the mass flowrate of the fluid. Means are provided to respond to incipient flow-induced changes in the amplitude of vibration by changing the power input to the excitation device as required to sustain the original amplitude of vibration. The fluid mass flowrate and density are determined from the required change in power input. The invention provides stable, rapid, and accurate measurements. It does not require bending of the fluid flow.
Development of one-dimensional computational fluid dynamics code 'GFLOW' for groundwater flow and contaminant transport analysis
Rahatgaonkar, P. S.; Datta, D.; Malhotra, P. K.; Ghadge, S. G. [Nuclear Power Corporation of India Ltd., R-2, Ent. Block, Nabhikiya Urja Bhavan, Anushakti Nagar, Mumbai - 400 094 (India)
Prediction of groundwater movement and contaminant transport in soil is an important problem in many branches of science and engineering. This includes groundwater hydrology, environmental engineering, soil science, agricultural engineering and also nuclear engineering. Specifically, in nuclear engineering it is applicable in the design of spent fuel storage pools and waste management sites in the nuclear power plants. Ground water modeling involves the simulation of flow and contaminant transport by groundwater flow. In the context of contaminated soil and groundwater system, numerical simulations are typically used to demonstrate compliance with regulatory standard. A one-dimensional Computational Fluid Dynamics code GFLOW had been developed based on the Finite Difference Method for simulating groundwater flow and contaminant transport through saturated and unsaturated soil. The code is validated with the analytical model and the benchmarking cases available in the literature. (authors)
The mathematical structure of multiphase thermal models of flow in porous media
- tions, Darcy's law for volumetric flow rates and an energy equation in terms of enthalpy. The model with the formulation and numerical solution of equations for modelling multicomponent, two-phase, thermal fluid flow is closed with an equation of state and phase equilibrium con- ditions that determine the distribution
Energy of eigen-modes in magnetohydrodynamic flows of ideal fluids
I. V. Khalzov; A. I. Smolyakov; V. I. Ilgisonis
Analytical expression for energy of eigen-modes in magnetohydrodynamic flows of ideal fluids is obtained. It is shown that the energy of unstable modes is zero, while the energy of stable oscillatory modes (waves) can assume both positive and negative values. Negative energy waves always correspond to non-symmetric eigen-modes -- modes that have a component of wave-vector along the equilibrium velocity. These results suggest that all non-symmetric instabilities in ideal MHD systems with flows are associated with coupling of positive and negative energy waves. As an example the energy of eigen-modes is calculated for incompressible conducting fluid rotating in axial magnetic field.
Fluid flow in the earth's crust plays an important role in a number of geologic processes. In carbonate reservoirs, fluid
the first order). The dynamic elastic properties of the rock are determined by adding the com- pliance steps, and thus the elastic properties of the rock, for the seismic modeling. The simulation allows us processes--hydraulic frac- turing or induced seismicity--depending on the fluid and rock properties
1. INTRODUCTION Fluid flows are often so complicated that laboratory
Nilsson, Johan
with vertical stratification. For a single-hemisphere basin, self-sustained oscillations of the flow and period of the oscillations are partly determined by the energy avail- able for vertical mixing if v, University of Stockholm, Sweden. 4Department of Geosciences, University of Bremen, Germany. 5Climate
Numerical modeling of multiphase plumes: a comparative study between two-fluid and mixed-fluid integral models�
Bhaumik, Tirtharaj
Understanding the physics of multiphase plumes and their simulation through numerical modeling has been an important area of research in recent times in the area of environmental fluid mechanics. The two renowned numerical modeling types...
Elimination of Adverse Leakage Flow in a Miniature Pediatric Centrifugal Blood Pump by Computational Fluid Dynamics
Paden, Brad
levitated centrifugal blood pump intended to deliver 0.3�1.5 l/min of support to neo- nates and infants computational fluid dy- namics (CFD) analysis of impeller refinements, we found that sec- ondary blades located by exten- sive in vitro model testing. Computational fluid dynamics (CFD) has been widely used
Device and method for measuring multi-phase fluid flow in a conduit having an abrupt gradual bend
Ortiz, M.G.
A system is described for measuring fluid flow in a conduit having an abrupt bend. The system includes pressure transducers, one disposed in the conduit at the inside of the bend and one or more disposed in the conduit at the outside of the bend but spaced a distance therefrom. The pressure transducers measure the pressure of fluid in the conduit at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the conduit. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the conduit elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow. 1 fig.
Approximate Dynamic Programming for Networks: Fluid Models and Constraint Reduction
Veatch, Michael H.
of approximating functions for the differential cost. The first contribution of this paper is identifying new or piece-wise quadratic. Fluid cost has been used to initialize the value iteration algorithm [5Approximate Dynamic Programming for Networks: Fluid Models and Constraint Reduction Michael H
A conservative Lagrangian scheme for solving compressible fluid flows with multiple internal energy equations
Shu, Chi-Wang
A conservative Lagrangian scheme for solving compressible fluid flows with multiple internal energy. In some of these ap- plications, multiple internal energy equations such as those for electron, ion developed which are designed to solve the internal energy equation directly. These schemes can be easily
Hydrothermal dolomites in SW Sardinia (Italy): evidence for a widespread late-Variscan fluid flow event
Boni, Maria
directly from the low-grade metamorphic lithotypes undergoing dolomitization, nor from the low-temperature across large areas of the Iglesiente�Sulcis mining district (SW Sardinia, Italy). The dolomite crops out within circulation cells, which were driven by high heat flow. Fluids originated in the underlying rocks
Multiphase fluid flow and time lapse UNLP, 11 Octubre de 2012
Santos, Juan
and time lapse seismics � p. #12;Introduction. III The analysis of CO2 underground storage safety and time lapse seismics � p. #12;Introduction. I Storage of CO2 in geological formations is a procedure project: Sleipner gas field (North Sea). Multiphase fluid flow and time lapse seismics � p. #12
Under consideration for publication in J. Fluid Mech. 1 Analytical studies of flow effects due to
Sen, Mihir
and temporal behaviour of the specific boundary. Steady streaming induced by oscillatory flows over wavy of the wavy surface in comparison to the viscous boundary layer formed over the vibrating wall. Investigating boundaries is presented. A Newtonian viscous fluid confined in an infinite channel with flexible walls
Dynamics of a confined dusty fluid in a sheared ion flow
Laishram, Modhuchandra; Sharma, Devendra; Kaw, Predhiman K. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)
Dynamics of an isothermally driven dust fluid is analyzed which is confined in an azimuthally symmetric cylindrical setup by an effective potential and is in equilibrium with an unconfined sheared flow of a streaming plasma. Cases are analyzed where the confining potential constitutes a barrier for the driven fluid, limiting its spatial extension and boundary velocity. The boundary effects entering the formulation are characterized by applying the appropriate boundary conditions and a range of solutions exhibiting single and multiple vortex are obtained. The equilibrium solutions considered in the cylindrical setup feature a transition from single to multiple vortex state of the driven flow. Effects of (i) the variation in dust viscosity, (ii) coupling between the driving and the driven fluid, and (iii) a friction determining the equilibrium dynamics of the driven system are characterized.
Flow of mantle fluids through the ductile lower crust: Heliumisotope trends
Kennedy, B. Mack; van Soest, Matthijs C.
Heat and mass are injected into the shallow crust when mantle fluids are able to flow through the ductile lower crust. Minimum 3He/4He ratios in surface fluids from the northern Basin and Range province, western North America increase systematically from low, crustal values in the east to high, mantle values in the west, a regional trend that correlates with the rates of active crustal deformation. The highest ratios occur where the extension and shear strain rates are greatest. The correspondence of helium isotope ratios and active trans-tensional deformation indicates a deformation enhanced permeability and that mantle fluids can penetrate the ductile lithosphere in regions even where there is no significant magmatism. Superimposed on the regional trend are local, high-{sup 3}He/{sup 4}He anomalies signifying hidden magmatic activity and/or deep fluid production with locally enhanced permeability, identifying zones with high resource potential, particularly for geothermal energy development.
Toward compressed DMD: spectral analysis of fluid flows using sub-Nyquist-rate PIV data
Tu, Jonathan H; Kutz, J Nathan; Shang, Jessica K
Dynamic mode decomposition (DMD) is a powerful and increasingly popular tool for performing spectral analysis of fluid flows. However, it requires data that satisfy the Nyquist-Shannon sampling criterion. In many fluid flow experiments, such data are impossible to capture. We propose a new approach that combines ideas from DMD and compressed sensing. Given a vector-valued signal, we take measurements randomly in time (at a sub-Nyquist rate) and project the data onto a low-dimensional subspace. We then use compressed sensing to identify the dominant frequencies in the signal and their corresponding modes. We demonstrate this method using two examples, analyzing both an artificially constructed test dataset and particle image velocimetry data collected from the flow past a cylinder. In each case, our method correctly identifies the characteristic frequencies and oscillatory modes dominating the signal, proving the proposed method to be a capable tool for spectral analysis using sub-Nyquist-rate sampling.
Use of Geophysical Techniques to Characterize Fluid Flow in a...
Broader source: Energy.gov (indexed) [DOE]
modeling with TOUGH and eTOUGH * Stochastic and deterministic joint inversion - Use seismic to provide the architecture of the system plus wells, - Use EMresistivity,...
Simultaneous Extrema in the Entropy Production for Steady-State Fluid Flow in Parallel Pipes
Niven, Robert K
Steady-state flow of an incompressible fluid in parallel pipes can simultaneously satisfy two contradictory extremum principles in the entropy production, depending on the flow conditions. For a constant total flow rate, the flow can satisfy (i) a pipe network minimum entropy production (MinEP) principle with respect to the flow rates, and (ii) the maximum entropy production (MaxEP) principle of Paltridge and Ziegler with respect to the choice of flow regime. The first principle - different to but allied to that of Prigogine - arises from the stability of the steady state compared to non-steady-state flows; it is proven for isothermal laminar and turbulent flows in parallel pipes with a constant power law exponent, but is otherwise invalid. The second principle appears to be more fundamental, driving the formation of turbulent flow in single and parallel pipes at higher Reynolds numbers. For constant head conditions, the flow can satisfy (i) a modified maximum entropy production (MaxEPMod) principle of \\v{Z}u...
Fluid Flow, Thermal History, and Diagenesis of the Cambrian-Ordovician Arbuckle Group and Overlying Units in South-Central Kansas
King, Bradley Donald
controlled during calcite precipitation. Ouachita tectonism caused tectonically valved and gravity-driven fluid flow sourced from the Anadarko basin and possibly involved sandstone aquifers or basement. Mechanisms of ancient fluid flow appear to contrast...
Classical analogous of quantum cosmological perfect fluid models
Batista, A B; Gon�alves, S V B; Tossa, J
Quantization in the mini-superspace of a gravity system coupled to a perfect fluid, leads to a solvable model which implies singularity free solutions through the construction of a superposition of the wavefunctions. We show that such models are equivalent to a classical system where, besides the perfect fluid, a repulsive fluid with an equation of state $p_Q = \\rho_Q$ is present. This leads to speculate on the true nature of this quantization procedure. A perturbative analysis of the classical system reveals the condition for the stability of the classical system in terms of the existence of an anti-gravity phase.
Hydrodynamical model for $J/?$ suppression and elliptic flow
A. K. Chaudhuri
In a hydrodynamic model, we have studied $J/\\psi$ suppression and elliptic flow in Au+Au collisions at RHIC energy $\\sqrt{s}$=200 GeV. At the initial time, $J/\\psi$'s are randomly distributed in the fluid. As the fluid evolve in time, the free streaming $J/\\psi$'s are dissolved if the local fluid temperature exceeds a melting temperature $T_{J/\\psi}$. Sequential melting of charmonium states ($\\chi_c$, $\\psi\\prime$ and $J/\\psi$), with melting temperatures $T_{\\chi_c}=T_{\\psi\\prime} \\approx 1.2T_c$, $T_{J/\\psi} \\approx2T_c$ and feed-down fraction $F\\approx 0.3$, is consistent with the PHENIX data on $J/\\psi$ suppression and near zero elliptic flow for $J/\\psi$'s. It is also shown that the model will require substantial regeneration of charmoniums, if the charmonium states dissolve at temperature close to the critical temperature, $T_{\\chi_c}=T_{\\psi\\prime} \\leq T_c$, $T_{J/\\psi}\\approx1.2T_c$. The regenerated charmoniums will have positive elliptic flow.
Non-Invasive Characterization Of A Flowing Multi-Phase Fluid Using Ultrasonic Interferometry
Sinha, Dipen N. (Los Alamos, NM)
An apparatus for noninvasively monitoring the flow and/or the composition of a flowing liquid using ultrasound is described. The position of the resonance peaks for a fluid excited by a swept-frequency ultrasonic signal have been found to change frequency both in response to a change in composition and in response to a change in the flow velocity thereof. Additionally, the distance between successive resonance peaks does not change as a function of flow, but rather in response to a change in composition. Thus, a measurement of both parameters (resonance position and resonance spacing), once calibrated, permits the simultaneous determination of flow rate and composition using the apparatus and method of the present invention.
Izgec, Omer
and its effect on fluid flow is numerical simulation. A 3D finite difference numerical model is developed based on Darcy-Brinkman formulation (DBF). Using the developed simulator a flow-based inversion approach is implemented to understand the connectivity...
Oscillatory motion based measurement method and sensor for measuring wall shear stress due to fluid flow
Armstrong, William D. (Laramie, WY); Naughton, Jonathan (Laramie, WY); Lindberg, William R. (Laramie, WY)
A shear stress sensor for measuring fluid wall shear stress on a test surface is provided. The wall shear stress sensor is comprised of an active sensing surface and a sensor body. An elastic mechanism mounted between the active sensing surface and the sensor body allows movement between the active sensing surface and the sensor body. A driving mechanism forces the shear stress sensor to oscillate. A measuring mechanism measures displacement of the active sensing surface relative to the sensor body. The sensor may be operated under periodic excitation where changes in the nature of the fluid properties or the fluid flow over the sensor measurably changes the amplitude or phase of the motion of the active sensing surface, or changes the force and power required from a control system in order to maintain constant motion. The device may be operated under non-periodic excitation where changes in the nature of the fluid properties or the fluid flow over the sensor change the transient motion of the active sensor surface or change the force and power required from a control system to maintain a specified transient motion of the active sensor surface.
Analytical modeling for the heat transfer in sheared flows of nanofluids
Ferrari, Claudio; L'vov, Victor S; Procaccia, Itamar; Rudenko, Oleksii; Boonkkamp, J H M ten Thije; Toschi, Federico
We developed a model for the enhancement of the heat flux by spherical and elongated nano- particles in sheared laminar flows of nano-fluids. Besides the heat flux carried by the nanoparticles the model accounts for the contribution of their rotation to the heat flux inside and outside the particles. The rotation of the nanoparticles has a twofold effect, it induces a fluid advection around the particle and it strongly influences the statistical distribution of particle orientations. These dynamical effects, which were not included in existing thermal models, are responsible for changing the thermal properties of flowing fluids as compared to quiescent fluids. The proposed model is strongly supported by extensive numerical simulations, demonstrating a potential increase of the heat flux far beyond the Maxwell-Garnet limit for the spherical nanoparticles. The road ahead which should lead towards robust predictive models of heat flux enhancement is discussed.
Analytical modeling for the heat transfer in sheared flows of nanofluids
Claudio Ferrari; Badr Kaoui; Victor S. L'vov; Itamar Procaccia; Oleksii Rudenko; J. H. M. ten Thije Boonkkamp; Federico Toschi
We developed a model for the enhancement of the heat flux by spherical and elongated nano- particles in sheared laminar flows of nano-fluids. Besides the heat flux carried by the nanoparticles the model accounts for the contribution of their rotation to the heat flux inside and outside the particles. The rotation of the nanoparticles has a twofold effect, it induces a fluid advection around the particle and it strongly influences the statistical distribution of particle orientations. These dynamical effects, which were not included in existing thermal models, are responsible for changing the thermal properties of flowing fluids as compared to quiescent fluids. The proposed model is strongly supported by extensive numerical simulations, demonstrating a potential increase of the heat flux far beyond the Maxwell-Garnet limit for the spherical nanoparticles. The road ahead which should lead towards robust predictive models of heat flux enhancement is discussed.
1985/1986 SOMED (School of Mines and Energy Development) project: The effect of temperature, fluid composition, and flow rate on sandstones: implications for enhanced oil recovery methods: Final report
Donahoe, R.J.
A low-temperature hydrothermal flow-through study was conducted experimentally examine fluid/rock interactions brought about in sandstones as a result of fluid injection enhanced oil recovery (EOR) methods. Such studies will eventually enable the development of a predictive model for fluid injection EOR methods. The design of the low-temperature hydrothermal flow-through system allows the accurate control of fluid flow rate (0.002-10 ml/min), temperature (0 to 300/sup 0/C) and pressure (1 to 500 bar) while flowing fluids through disaggregated solid samples. Samples of St. Peter Sandstone and two different sandstones of the Norphlet Formation from southern Alabama were interacted with distilled, deionized water and a 1% HC1 solution at 250/sup 0/C, 300 bar and 0.1 or 0.5 ml/min fluid flow rate. Solids were analyzed by x-ray powder diffraction and scanning electron microscopy. Fluid samples were analyzed by atomic absorption spectrophotometry and combination pH electrode. A variety of processes which occur in sandstones subjected to fluid injection EOR methods were documented experimentally. Processes damaging to reservoir permeability included iron fouling, silica fouling, migration of clay fines, and precipitation of other secondary phases. Processes resulting in reservoir stimulation involved the dissolution of sandstone framework and/or authigenic mineral constituents. The most successful fluid injection stimulation can be expected for arkosic sandstones containing high percentages of K-feldspar and illite relative to kaolinite, chlorite and smectite, using dilute HCl injection solutions and high fluid flow rates. Fluid chemical data indicate that equilibrium between the solid and injection fluid is not approached for any of the experiments. Therefore, it does not appear that chemical equilibrium computer programs can be used to model these low-temperature reactions. 12 refs., 11 figs., 4 tabs.
Particle-fluid-structure interaction for debris flow impact on flexible barriers
A. Leonardi; F. K. Wittel; M. Mendoza; R. Vetter; H. J. Herrmann
Flexible barriers are increasingly used for the protection from debris flow in mountainous terrain due to their low cost and environmental impact. However, a numerical tool for rational design of such structures is still missing. In this work, a hybrid computational framework is presented, using a total Lagrangian formulation of the Finite Element Method (FEM) to represent a flexible barrier. The actions exerted on the structure by a debris flow are obtained from simultaneous simulations of the flow of a fluid-grain mixture, using two conveniently coupled solvers: the Discrete Element Method (DEM) governs the motion of the grains, while the free-surface non-Newtonian fluid phase is solved using the Lattice-Boltzmann Method (LBM). Simulations on realistic geometries show the dependence of the momentum transfer on the barrier on the composition of the debris flow, challenging typical assumptions made during the design process today. In particular, we demonstrate that both grains and fluid contribute in a non-negligible way to the momentum transfer. Moreover, we show how the flexibility of the barrier reduces its vulnerability to structural collapse, and how the stress is distributed on its fabric, highlighting potential weak points.
Method and apparatus for optical Doppler tomographic imaging of fluid flow velocity in highly scattering media
Nelson, John Stuart (Laguna Niguel, CA); Milner, Thomas Edward (Irvine, CA); Chen, Zhongping (Irvine, CA)
Optical Doppler tomography permits imaging of fluid flow velocity in highly scattering media. The tomography system combines Doppler velocimetry with high spatial resolution of partially coherent optical interferometry to measure fluid flow velocity at discrete spatial locations. Noninvasive in vivo imaging of blood flow dynamics and tissue structures with high spatial resolutions of the order of 2 to 10 microns is achieved in biological systems. The backscattered interference signals derived from the interferometer may be analyzed either through power spectrum determination to obtain the position and velocity of each particle in the fluid flow sample at each pixel, or the interference spectral density may be analyzed at each frequency in the spectrum to obtain the positions and velocities of the particles in a cross-section to which the interference spectral density corresponds. The realized resolutions of optical Doppler tomography allows noninvasive in vivo imaging of both blood microcirculation and tissue structure surrounding the vessel which has significance for biomedical research and clinical applications.
Numerical Simulation of Compositional Fluid Flow in Porous Media
Ewing, Richard E.
variables is developed for modeling the enhanced oil recovery pro- cesses. A mixed #12;nite element method to predict the reservoir performance under various exploita- tion schemes. In many enhanced oil recovery. Computational results for two- and three-phase multi-component uid ow occurring in enhanced oil re- covery
Numerical studies on two-way coupled fluid flow and geomechanics in hydrate deposits
Kim, J.
A. 2008. Modeling of Geomechanics in Naturally Fracturedcoupling porous flow and geomechanics. Soc. Pet. Eng. J. 11(a reservoir simulator and a geomechanics module. Soc. Pet.
COMPUTATIONAL FLUID DYNAMICS MODELING OF SOLID OXIDE FUEL CELLS Ugur Pasaogullari and Chao-dimensional model has been developed to simulate solid oxide fuel cells (SOFC). The model fully couples current density operation. INTRODUCTION Solid oxide fuel cells (SOFC) are among possible candidates
Geologic constraints to fluid flow in the Jurassic Arab D reservoir, eastern Saudi Arabia
Laing, J.E. (Saudi Aramco, Dhahran (Saudi Arabia))
A giant oil field located in eastern Saudi Arabia has produced several billion barrels of 37{degree} API oil from fewer than 100 wells. The Upper Jurassic Arab Formation is the main producing unit, and is made up of a series of upward-shoaling carbonate and anhydrite members. Porous carbonates of the Arab D member make up the principle oil reservoir, and overlying Arab D anhydrite provides the seal. Principal reservoir facies are stromatoporoid-coral and skeletal grainstones. Reservoir drive is currently provided by flank water injection. Despite more than 30 years of flank water injection (1.5 billion bbl) into the northern area of the field, a thick oil column remains in the Arab D reservoir. Geological factors which affect fluid flow in this area are (1) a downdip facies change from permeable skeletal-stromatoporoid limestone to less permeable micritic limestone, (2) vertical permeability barriers resulting from shoaling-upward cycles, (3) a downdip tar mat, (4) dolomite along the flanks in the upper portion of the reservoir, (5) highly permeable intervals within the skeletal-stromatoporoid limestone, and (6) an updip, north to south facies change from predominantly stromatoporoid-coral grainstone to skeletal grainstone. These factors are considered in reservoir modeling, simulation studies, and planning locations for both water injection and producer wells.
Viscous quark-gluon plasma model through fluid QCD approach
Djun, T. P., E-mail: email@example.com [Graduate Study in Material Science, University of Indonesia, Kampus UI Salemba, Jakarta 10430, Indonesia and Group for Theoretical and Computational Physics, Research Center for Physics, Indonesian Institute of Sciences, Kompleks Puspiptek Serpong, T (Indonesia); Soegijono, B.; Mart, T. [Graduate Study in Material Science, University of Indonesia, Kampus UI Salemba, Jakarta 10430, Indonesia and Department of Physics, University of Indonesia, Kampus UI Depok, Depok 16424 (Indonesia); Handoko, L. T., E-mail: firstname.lastname@example.com, E-mail: email@example.com [Group for Theoretical and Computational Physics, Research Center for Physics, Indonesian Institute of Sciences, Kompleks Puspiptek Serpong, Tangerang 15310, Indonesia and Research Center for Informatics, Indonesia Institute of Sciences, Kompleks LIPI (Indonesia)
A Lagrangian density for viscous quark-gluon plasma has been constructed within the fluid-like QCD framework. Gauge symmetry is preserved for all terms inside the Lagrangian, except for the viscous term. The transition mechanism from point particle field to fluid field, and vice versa, are discussed. The energy momentum tensor that is relevant to the gluonic plasma having the nature of fluid bulk of gluon sea is derived within the model. By imposing conservation law in the energy momentum tensor, shear viscosity appears as extractable from the equation.
Dispersed Fluid Flow in Fractured Reservoirs- an Analysis of
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USER�S GUIDE of TOUGH2-EGS: A Coupled Geomechanical and Reactive Geochemical Simulator for Fluid and Heat Flow in Enhanced Geothermal Systems Version 1.0
Fakcharoenphol, Perapon [Colorado School of Mines; Xiong, Yi [Colorado School of Mines; Hu, Litang; Winterfeld, Philip H. [Colorado School of Mines; Xu, Tianfu [Lawrence Berkeley National Laboratory; Wu, Yu-Shu [Colorado School of Mines
TOUGH2-EGS is a numerical simulation program coupling geomechanics and chemical reactions for fluid and heat flows in porous media and fractured reservoirs of enhanced geothermal systems. The simulator includes the fully-coupled geomechanical (THM) module, the fully-coupled geochemical (THC) module, and the sequentially coupled reactive geochemistry (THMC) module. The fully-coupled flow-geomechanics model is developed from the linear elastic theory for the thermo-poro-elastic system and is formulated with the mean normal stress as well as pore pressure and temperature. The chemical reaction is sequentially coupled after solution of flow equations, which provides the flow velocity and phase saturation for the solute transport calculation at each time step. In addition, reservoir rock properties, such as porosity and permeability, are subjected to change due to rock deformation and chemical reactions. The relationships between rock properties and geomechanical and chemical effects from poro-elasticity theories and empirical correlations are incorporated into the simulator. This report provides the user with detailed information on both mathematical models and instructions for using TOUGH2-EGS for THM, THC or THMC simulations. The mathematical models include the fluid and heat flow equations, geomechanical equation, reactive geochemistry equations, and discretization methods. Although TOUGH2-EGS has the capability for simulating fluid and heat flows coupled with both geomechanical and chemical effects, it is up to the users to select the specific coupling process, such as THM, THC, or THMC in a simulation. There are several example problems illustrating the applications of this program. These example problems are described in details and their input data are presented. The results demonstrate that this program can be used for field-scale geothermal reservoir simulation with fluid and heat flow, geomechanical effect, and chemical reaction in porous and fractured media.
Fluid flow release regulating device, ERIP {number_sign}624: Final report
DOE/ERIP project {number_sign}624 ``Fluid Flow Release Regulating Device`` designed, constructed, tested, and installed a rubber crest gate for regulating water levels at an impoundment such as a hydroelectric dam. A 92 foot long by 27 inch high rubber panel was installed in January 1997. Initial results were good until fabric degradation internal to the rubber caused loss of stiffness. Substitutes for the failed fabric are being tested. The project will continue after DOE participation terminates.
Continued development of a semianalytical solution for two-phase fluid and heat flow in a porous medium
Doughty, C.; Pruess, K. [Lawrence Berkeley Lab., CA (United States)
Over the past few years the authors have developed a semianalytical solution for transient two-phase water, air, and heat flow in a porous medium surrounding a constant-strength linear heat source, using a similarity variable {eta} = r/{radical}t. Although the similarity transformation approach requires a simplified geometry, all the complex physical mechanisms involved in coupled two-phase fluid and heat flow can be taken into account in a rigorous way, so that the solution may be applied to a variety of problems of current interest. The work was motivated by adverse to predict the thermohydrological response to the proposed geologic repository for heat-generating high-level nuclear wastes at Yucca Mountain, Nevada, in a partially saturated, highly fractured volcanic formation. The paper describes thermal and hydrologic conditions near the heat source; new features of the model; vapor pressure lowering; and the effective-continuum representation of a fractured/porous medium.
Computational fluid dynamics modeling of coal gasification in a pressurized spout-fluid bed
Zhongyi Deng; Rui Xiao; Baosheng Jin; He Huang; Laihong Shen; Qilei Song; Qianjun Li [Southeast University, Nanjing (China). Key Laboratory of Clean Coal Power Generation and Combustion Technology of Ministry of Education
Computational fluid dynamics (CFD) modeling, which has recently proven to be an effective means of analysis and optimization of energy-conversion processes, has been extended to coal gasification in this paper. A 3D mathematical model has been developed to simulate the coal gasification process in a pressurized spout-fluid bed. This CFD model is composed of gas-solid hydrodynamics, coal pyrolysis, char gasification, and gas phase reaction submodels. The rates of heterogeneous reactions are determined by combining Arrhenius rate and diffusion rate. The homogeneous reactions of gas phase can be treated as secondary reactions. A comparison of the calculated and experimental data shows that most gasification performance parameters can be predicted accurately. This good agreement indicates that CFD modeling can be used for complex fluidized beds coal gasification processes. 37 refs., 7 figs., 5 tabs.
Electromechanics and electrorheology of fluid flow with internal micro-particle electrorotation
Huang, Hsin-Fu
The negative electrorheological responses of two dimensional Couette and Poiseuille flows with internal micro-particle electrorotation are modeled and analyzed via a set of "fully continuum mechanical modeling field ...
Numerical method for fluid flow and heat transfer in magnetohydrodynamic flow
Kim, C.N.; Abdou, M.A.
A new numerical algorithm was developed to provide a fully detailed flow field in liquid metal MHD flow with a relatively large Hartmann number and interaction parameter. The algorithm includes the effects of advection and diffusion, and is capable of predicting momentum and heat transfer in MHD flows. Using this algorithm, an incompressible, viscous, three-dimensional MHD flow in a square duct is investigated at a low magnetic Reynolds number by means of the finite volume method. The velocity and temperature profiles are obtained in the developing region for constant wall temperature. The result shows that large velocities are obtained near the insulating walls parallel to the magnetic field. Also, near the perfectly conducting walls perpendicular to the field, a velocity profile like a Hartmann layer is obtained. In association with the velocity profiles, Nusselt number at the insulating walls (with side layer) is seen to be larger than that at the perfectly conducting walls (with Hartmann layer).
Physiochemical Evidence of Faulting Processes and Modeling of Fluid in Evolving Fault Systems in Southern California
Boles, James [Professor
Our study targets recent (Plio-Pleistocene) faults and young (Tertiary) petroleum fields in southern California. Faults include the Refugio Fault in the Transverse Ranges, the Ellwood Fault in the Santa Barbara Channel, and most recently the Newport- Inglewood in the Los Angeles Basin. Subsurface core and tubing scale samples, outcrop samples, well logs, reservoir properties, pore pressures, fluid compositions, and published structural-seismic sections have been used to characterize the tectonic/diagenetic history of the faults. As part of the effort to understand the diagenetic processes within these fault zones, we have studied analogous processes of rapid carbonate precipitation (scaling) in petroleum reservoir tubing and manmade tunnels. From this, we have identified geochemical signatures in carbonate that characterize rapid CO2 degassing. These data provide constraints for finite element models that predict fluid pressures, multiphase flow patterns, rates and patterns of deformation, subsurface temperatures and heat flow, and geochemistry associated with large fault systems.
Long-wave models of thin film fluid dynamics
A. J. Roberts
Centre manifold techniques are used to derive rationally a description of the dynamics of thin films of fluid. The derived model is based on the free-surface $\\eta(x,t)$ and the vertically averaged horizontal velocity $\\avu(x,t)$. The approach appears to converge well and has significant differences from conventional depth-averaged models.
A Robust Four-Fluid Transient Flow Simulator as an Analysis and Decision Making Tool for Dynamic Kill Operation�
Haghshenas, Arash
The worst scenario of drilling operation is blowout which is uncontrolled flow of formation fluid into the wellbore. Blowouts result in environmental damage with potential risk of injuries and fatalities. Although not all ...
Geophysical Fluid Dynamics Laboratory general circulation model investigation of the indirect radiative effects
Russell, Lynn
Geophysical Fluid Dynamics Laboratory general circulation model investigation of the indirect Corporation for Atmospheric Research, Geophysical Fluid Dynamics Laboratory, Princeton, New Jersey, USA V. Ramaswamy, Paul A. Ginoux, and Larry W. Horowitz Geophysical Fluid Dynamics Laboratory, Princeton, New
The influence of fluid flow through granitic crust: a thermo-tectonic study in and on Mont Blanc
Glasgow, University of
The influence of fluid flow through granitic crust: a thermo-tectonic study in and on Mont Blanc Tim Dempster, Cristina Persano and Zoe Shipton *email@example.com Granitic and gneissose within a evolving mountain zone, the metasomatic influence of fluids in granite gneiss and the resulting
Continuum-particle hybrid coupling for mass, momentum and energy transfers in unsteady fluid flow
R. Delgado-Buscalioni; P. V. Coveney
The aim of hybrid methods in simulations is to communicate regions with disparate time and length scales. Here, a fluid described at the atomistic level within an inner region P is coupled to an outer region C described by continuum fluid dynamics. The matching of both descriptions of matter is made across an overlapping region and, in general, consists of a two-way coupling scheme (C->P and P->C) which conveys mass, momentum and energy fluxes. The contribution of the hybrid scheme hereby presented is two-fold: first it treats unsteady flows and, more importantly, it handles energy exchange between both C and P regions. The implementation of the C->P coupling is tested here using steady and unsteady flows with different rates of mass, momentum and energy exchange. In particular, relaxing flows described by linear hydrodynamics (transversal and longitudinal waves) are most enlightening as they comprise the whole set of hydrodynamic modes. Applying the hybrid coupling scheme after the onset of an initial perturbation, the cell-averaged Fourier components of the flow variables in the P region (velocity, density, internal energy, temperature and pressure) evolve in excellent agreement with the hydrodynamic trends. It is also shown that the scheme preserves the correct rate of entropy production. We discuss some general requirements on the coarse-grained length and time scales arising from both the characteristic microscopic and hydrodynamic scales.
Large Matched-Index-of-Refraction (MIR) Flow Systems for International Collaboration In Fluid Mechanics
Donald M. McEligot; Stefan Becker; Hugh M. McIlroy, Jr.
In recent international collaboration, INL and Uni. Erlangen have developed large MIR flow systems which can be ideal for joint graduate student education and research. The benefit of the MIR technique is that it permits optical measurements to determine flow characteristics in complex passages and around objects to be obtained without locating a disturbing transducer in the flow field and without distortion of the optical paths. The MIR technique is not new itself; others employed it earlier. The innovation of these MIR systems is their large size relative to previous experiments, yielding improved spatial and temporal resolution. This report will discuss the benefits of the technique, characteristics of the systems and some examples of their applications to complex situations. Typically their experiments have provided new fundamental understanding plus benchmark data for assessment and possible validation of computational thermal fluid dynamic codes.
Modeling complex biological flows in multi-scale systems using the APDEC framework
Modeling complex biological flows in multi-scale systems using the APDEC framework David Trebotich methods are based on higher-order finite difference methods in complex geometry with adaptivity-mail: email@example.com Abstract. We have developed advanced numerical algorithms to model biological fluids
Viscoelastic fluid flow in a 2D channel bounded above by a deformable finite thickness elastic wall
Chakraborty, Debadi
The steady flow of three viscoelastic fluids (Oldroyd-B, FENE-P, and Owens model for blood) in a two-dimensional channel, partly bound by a deformable, finite thickness neo-Hookean solid, is computed. The limiting Weissenberg number beyond which computations fail to converge is found to increase with increasing dimensionless solid elasticity parameter {\\Gamma}, following the trend Owens > FENE- P > Oldroyd-B. The highly shear thinning nature of Owens model leads to the elastic solid always collapsing into the channel, for the wide range of values of {\\Gamma} considered here. In the case of the FENE-P and Oldroyd-B models, however, the fluid-solid interface can be either within the channel, or bulge outwards, depending on the value of {\\Gamma}. This behaviour differs considerably from predictions of earlier models that treat the deformable solid as a zero-thickness membrane, in which case the membrane always lies within the channel. The capacity of the solid wall to support both pressure and shear stress, in c...
Status of the TOUGH-FLAC simulator and recent applications related to coupled fluid flow and crustal deformations
Rutqvist, J.
This paper presents recent advancement in and applications of TOUGH-FLAC, a simulator for multiphase fluid flow and geomechanics. The TOUGH-FLAC simulator links the TOUGH family multiphase fluid and heat transport codes with the commercial FLAC{sup 3D} geomechanical simulator. The most significant new TOUGH-FLAC development in the past few years is a revised architecture, enabling a more rigorous and tight coupling procedure with improved computational efficiency. The applications presented in this paper are related to modeling of crustal deformations caused by deep underground fluid movements and pressure changes as a result of both industrial activities (the In Salah CO{sub 2} Storage Project and the Geysers Geothermal Field) and natural events (the 1960s Matsushiro Earthquake Swarm). Finally, the paper provides some perspectives on the future of TOUGH-FLAC in light of its applicability to practical problems and the need for high-performance computing capabilities for field-scale problems, such as industrial-scale CO{sub 2} storage and enhanced geothermal systems. It is concluded that despite some limitations to fully adapting a commercial code such as FLAC{sup 3D} for some specialized research and computational needs, TOUGH-FLAC is likely to remain a pragmatic simulation approach, with an increasing number of users in both academia and industry.
Modeling Fluid Flow in Natural Systems, Model Validation and Demonstration
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Viscous potential flow analysis of electrified miscible finitely conducting fluid through porous media
Obied Allah, M. H. [Department of Mathematics, Faculty of Science, Assiut University, Assiut (Egypt)
In this work, a viscous potential flow analysis is used to investigate capillary surface waves between two horizontal finite fluid layers. The two layers have finite conductivities and admit mass and heat transfer. A general dispersion relation is derived. The presence of finite conductivities together with the dielectric permeabilities makes the horizontal electric field play a dual role in the stability criterion. The phenomenon of negative viscosity is observed. A new growth rate parameter, depending on the kinematical viscosity of the lower fluid layer, is found and has a stabilizing effect on the unstable modes. The growth rates and neutral stability curve are given and applied to air-water interface. The effects of various parameters are discussed for the Kelvin-Helmholtz and the Rayleigh-Taylor instabilities.
TOUGH2: A general-purpose numerical simulator for multiphase fluid and heat flow
Pruess, K.
TOUGH2 is a numerical simulation program for nonisothermal flows of multicomponent, multiphase fluids in porous and fractured media. The chief applications for which TOUGH2 is designed are in geothermal reservoir engineering, nuclear waste disposal, and unsaturated zone hydrology. A successor to the TOUGH program, TOUGH2 offers added capabilities and user features, including the flexibility to handle different fluid mixtures, facilities for processing of geometric data (computational grids), and an internal version control system to ensure referenceability of code applications. This report includes a detailed description of governing equations, program architecture, and user features. Enhancements in data inputs relative to TOUGH are described, and a number of sample problems are given to illustrate code applications. 46 refs., 29 figs., 12 tabs.
A Parallel Implementation of the TOUGH2 Software Package for Large Scale Multiphase Fluid and Heat Flow Simulations
Elmroth, Erik
A Parallel Implementation of the TOUGH2 Software Package for Large Scale Multiphase Fluid and Heat groundwater flow related problems such as nuclear waste isolation, environmental remediation, and geothermal with ������� ��� blocks in a Yucca Mountain nuclear waste site study. Keywords. Ground water flow, grid partitioning
A Parallel Implementation of the TOUGH2 Software Package for Large Scale Multiphase Fluid and Heat Flow Simulations
Elmroth, Erik
A Parallel Implementation of the TOUGH2 Software Package for Large Scale Multiphase Fluid and Heat groundwater flow related problems such as nuclear waste isolation, environmental remediation, and geothermal 6 blocks in a Yucca Mountain nuclear waste site study. Keywords. Ground water flow, grid
Bulletin of the Seismological Society of America, Vol. 94, No. 5, pp. 18171830, October 2004 Faulting Induced by Forced Fluid Injection and Fluid Flow Forced by
is a technique used to image the volume of rock stimulated by hydraulic fracturing (Al- bright and Pearson, 1982. The method has been applied in devel- oping hot dry rock reservoirs (e.g., Pine and Batchelor, 1984; House al., 2003). Beyond mapping gross structure and fluid-flow paths, rela- tive source location
Study of Laminar Flow Forced Convection Heat Transfer Behavior of a Phase Change Material Fluid
Ravi, Gurunarayana
with constant peripheral temperature and uniform axial and peripheral temperature, were considered in the case of circular tubes. An effective specific heat technique was used to model the phase change process assuming a hydrodynamically fully-developed flow...
Beckermann, Christoph
. By combining Darcy's law, which governs fluid flow in the mushy zone, with the equation for Stokes' flow, which governs the motion of slow-flowing pure liquid, it is possible to derive a momentum equation that is valid everywhere in the solution domain. A pressure equation is then derived by combining this momentum equation
The Properties of Confined Water and Fluid Flow at the Nanoscale
Schwegler, E; Reed, J; Lau, E; Prendergast, D; Galli, G; Grossman, J C; Cicero, G
This project has been focused on the development of accurate computational tools to study fluids in confined, nanoscale geometries, and the application of these techniques to probe the structural and electronic properties of water confined between hydrophilic and hydrophobic substrates, including the presence of simple ions at the interfaces. In particular, we have used a series of ab-initio molecular dynamics simulations and quantum Monte Carlo calculations to build an understanding of how hydrogen bonding and solvation are modified at the nanoscale. The properties of confined water affect a wide range of scientific and technological problems - including protein folding, cell-membrane flow, materials properties in confined media and nanofluidic devices.
The flow and heat transfer in a viscous fluid over an unsteady stretching surface
Ene, Remus-Daniel; Marinca, Bogdan
In this paper we have studied the flow and heat transfer in a viscous fluid by a horizontal sheet. The stretching rate and temperature of the sheet vary with time. The governing equations for momentum and thermal energy are reduced to ordinary differential equations by means of similarity transformation. These equations are solved approximately by means of the Optimal Homotopy Asymptotic Method (OHAM) which provides us with a convenient way to control the convergence of approximation solutions and adjust convergence rigorous when necessary. Some examples are given and the results obtained reveal that the proposed method is effective and easy to use.
Computational Fluid Dynamics (CFD) Modeling for High Rate Pulverized Coal Injection (PCI) into the Blast Furnace
Dr. Chenn Zhou
Pulverized coal injection (PCI) into the blast furnace (BF) has been recognized as an effective way to decrease the coke and total energy consumption along with minimization of environmental impacts. However, increasing the amount of coal injected into the BF is currently limited by the lack of knowledge of some issues related to the process. It is therefore important to understand the complex physical and chemical phenomena in the PCI process. Due to the difficulty in attaining trus BF measurements, Computational fluid dynamics (CFD) modeling has been identified as a useful technology to provide such knowledge. CFD simulation is powerful for providing detailed information on flow properties and performing parametric studies for process design and optimization. In this project, comprehensive 3-D CFD models have been developed to simulate the PCI process under actual furnace conditions. These models provide raceway size and flow property distributions. The results have provided guidance for optimizing the PCI process.
A photographic study of fluid flow theory for two-dimensional laminar flow around solid bodies
Lee, Wen Ho
Table 2. Mater Table, a Bottom View 3. A Top View of Water Table 4. A View of the Mhole Equipment 5. Dimensions of the Mater Table 6. Copper Tank and Rubber Bodies 7. Diagram oi' Stream Velocity H. Diagram of Stream Function 9. Diagram of grad P... 22. Source with Strength 0 = 5 in /min 3 23. Source with Strength Q - 10 in /min 24. The Streamlines of' Figure 22 25. The StreamC. ines of' Figure 23 26. Rectilinear Flow with U 0. 08 f't/sec around an 25 26 26 27 27 28 Airfoil with Angle...
Energy Flow Models for the Steel Industry
Hyman, B.; Andersen, J. P.
Energy patterns in the U. S. steel industry are examined using several models. First is an end-use model based on data in the 1994 Manufacturing Energy Consumption Survey (MECS). Then a seven-step process model is presented and material flow through...
Energy Flow Models for the Steel Industry�
Hyman, B.; Andersen, J. P.
each step is calibrated against Commerce Dept. data. Third, a detailed energy flow model is presented for coke ovens and blast furnaces, two very energy-intensive steps in our seven step model of steelmaking. This process-step model is calibrated...
GROUNDWATER FLOW MODELS C. P. Kumar
Kumar, C.P.
GROUNDWATER FLOW MODELS C. P. Kumar Scientist `E1' National Institute of Hydrology Roorkee � 247667 (Uttaranchal) 1.0 INTRODUCTION The use of groundwater models is prevalent in the field of environmental science, groundwater models are being applied to predict the transport of contaminants for risk evaluation. In general
Determination of Transport Properties From Flowing Fluid Temperature LoggingIn Unsaturated Fractured Rocks: Theory And Semi-Analytical Solution
Mukhopadhyay, Sumit; Tsang, Yvonne W.
Flowing fluid temperature logging (FFTL) has been recently proposed as a method to locate flowing fractures. We argue that FFTL, backed up by data from high-precision distributed temperature sensors, can be a useful tool in locating flowing fractures and in estimating the transport properties of unsaturated fractured rocks. We have developed the theoretical background needed to analyze data from FFTL. In this paper, we present a simplified conceptualization of FFTL in unsaturated fractured rock, and develop a semianalytical solution for spatial and temporal variations of pressure and temperature inside a borehole in response to an applied perturbation (pumping of air from the borehole). We compare the semi-analytical solution with predictions from the TOUGH2 numerical simulator. Based on the semi-analytical solution, we propose a method to estimate the permeability of the fracture continuum surrounding the borehole. Using this proposed method, we estimated the effective fracture continuum permeability of the unsaturated rock hosting the Drift Scale Test (DST) at Yucca Mountain, Nevada. Our estimate compares well with previous independent estimates for fracture permeability of the DST host rock. The conceptual model of FFTL presented in this paper is based on the assumptions of single-phase flow, convection-only heat transfer, and negligible change in system state of the rock formation. In a sequel paper [Mukhopadhyay et al., 2008], we extend the conceptual model to evaluate some of these assumptions. We also perform inverse modeling of FFTL data to estimate, in addition to permeability, other transport parameters (such as porosity and thermal conductivity) of unsaturated fractured rocks.
Fuel cell assembly fluid flow plate having conductive fibers and rigidizing material therein
Walsh, Michael M. (Fairfield, CT)
A fluid flow plate is preferably formed with three initial sections, for instance, two layers of conductive (e.g., metal) fibers and a barrier material (e.g., metal foil) which is interposed between the two layers. For example, sintering of these three sections can provide electrical path(s) between outer faces of the two layers. Then, the sintered sections can be, for instance, placed in a mold for forming of flow channel(s) into one or more of the outer faces. Next, rigidizing material (e.g., resin) can be injected into the mold, for example, to fill and/or seal space(s) about a conductive matrix of the electrical path(s). Preferably, abrading of surface(s) of the outer face(s) serves to expose electrical contact(s) to the electrical path(s).
Mechanical Engineering ME 3720 FLUID MECHANICS
Panchagnula, Mahesh
. Fundamentals of fluid flow; fluid statics; systems, and control volumes; continuity, momentum and energy physical model results to prototype 10. Use Moody chart to calculate friction losses in pipe flows 11 equations; dynamic similitude; One-dimensional compressible flow. The objective(s) of this course is (are
Adaptive Finite element approximation of steady flows of incompressible fluids with implicit power-law-like rheology
Christian Kreuzer; Endre S�li
We develop the a posteriori error analysis of finite element approximations of implicit power-law-like models for viscous incompressible fluids. The Cauchy stress and the symmetric part of the velocity gradient in the class of models under consideration are related by a, possibly multi--valued, maximal monotone $r$-graph, with $\\frac{2d}{d+1}finite element residual, as well as the local stability of the error bound. We then consider an adaptive finite element approximation of the problem, and, under suitable assumptions, we show the weak convergence of the adaptive algorithm to a weak solution of the boundary-value problem. The argument is based on a variety of weak compactness techniques, including Chacon's biting lemma and a finite element counterpart of the Acerbi--Fusco Lipschitz truncation of Sobolev functions, introduced by L. Diening, C. Kreuzer and E. S\\"uli [Finite element approximation of steady flows of incompressible fluids with implicit power-law-like rheology. SIAM J. Numer. Anal., 51(2), 984--1015].
High-heat-flux removal by phase-change fluid and particulate flow
Gorbis, Z.R.; Raffray, A.R.; Abdou, M.A. (Univ. of California, Los Angeles (United States))
A new concept based on particulate flow in which either or both the particulates and the fluid could undergo phase changes is proposed. The presence of particulates provides not only a mechanism for additional heat removal through phase change but also the potential for increasing the rate of heat transfer by enhancing convection through surface region/bulk [open quotes]mixing[close quotes], by enhancing radiation, particularly for high-temperature cases; and for the case of multiphase fluid, by enhancing the boiling process. One particularly interesting coolant system based on this concept is [open quotes]subcooled boiling water-ice particulate[close quotes] flow. A preliminary analysis of this coolant system is presented, the results of which indicate that such a coolant system is better applied for cooling of relatively small surface areas with high local heat fluxes, where a conventional cooling system would come short of providing the required heat removal at acceptable coolant pressure levels. 14 refs., 8 figs.
Analysis of Refrigerant Flow and Deformation for a Flexible Short-Tube using a Finite Element Model
O'Neal, D.L.; Bassiouny, R.
reliability. Short-tubes have either a constant inner dia- meter flow channel or a tapered channel with a smallAbstract A finite element model was used to simulate single-phase flow of R-22 through flexible short-tubes. The numerical model included the fluid... in the flow area. The more flexible (5513 kPa) short-tube restricted the mass flow rate more than the most rigid (9889 kPa) short-tube used in this study. The mass flow rates estimated with the finite element model were as much as 14% higher than those from...
Numerical schemes for dynamically orthogonal equations of stochastic fluid and ocean flows
Ueckermann, M.P., E-mail: firstname.lastname@example.com [Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Mass. Avenue, Cambridge, MA 02139 (United States); Lermusiaux, P.F.J., E-mail: firstname.lastname@example.com [Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Mass. Avenue, Cambridge, MA 02139 (United States)] [Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Mass. Avenue, Cambridge, MA 02139 (United States); Sapsis, T.P., E-mail: firstname.lastname@example.com [Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Mass. Avenue, Cambridge, MA 02139 (United States)
The quantification of uncertainties is critical when systems are nonlinear and have uncertain terms in their governing equations or are constrained by limited knowledge of initial and boundary conditions. Such situations are common in multiscale, intermittent and non-homogeneous fluid and ocean flows. The dynamically orthogonal (DO) field equations provide an adaptive methodology to predict the probability density functions of such flows. The present work derives efficient computational schemes for the DO methodology applied to unsteady stochastic Navier-Stokes and Boussinesq equations, and illustrates and studies the numerical aspects of these schemes. Semi-implicit projection methods are developed for the mean and for the DO modes, and time-marching schemes of first to fourth order are used for the stochastic coefficients. Conservative second-order finite-volumes are employed in physical space with new advection schemes based on total variation diminishing methods. Other results include: (i) the definition of pseudo-stochastic pressures to obtain a number of pressure equations that is linear in the subspace size instead of quadratic; (ii) symmetric advection schemes for the stochastic velocities; (iii) the use of generalized inversion to deal with singular subspace covariances or deterministic modes; and (iv) schemes to maintain orthonormal modes at the numerical level. To verify our implementation and study the properties of our schemes and their variations, a set of stochastic flow benchmarks are defined including asymmetric Dirac and symmetric lock-exchange flows, lid-driven cavity flows, and flows past objects in a confined channel. Different Reynolds number and Grashof number regimes are employed to illustrate robustness. Optimal convergence under both time and space refinements is shown as well as the convergence of the probability density functions with the number of stochastic realizations.
Buscheck, Timothy Eric
There has been an increasing interest in probabilistic modeling of hydrogeologic systems. The classical approach to groundwater modeling has been deterministic in nature, where individual layers and formations are assumed to be uniformly homogeneous. Even in the case of complex heterogeneous systems, the heterogeneities describe the differences in parameter values between various layers, but not within any individual layer. In a deterministic model a single-number is assigned to each hydrogeologic parameter, given a particular scale of interest. However, physically there is no such entity as a truly uniform and homogeneous unit. Single-number representations or deterministic predictions are subject to uncertainties. The approach used in this work models such uncertainties with probabilistic parameters. The resulting statistical distributions of output variables are analyzed. A numerical algorithm, based on axiomatic principles of probability theory, performs arithmetic operations between probability distributions. Two subroutines are developed from the algorithm and incorporated into the computer program TERZAGI, which solves groundwater flow problems in saturated, multi-dimensional systems. The probabilistic computer program is given the name, PROGRES. The algorithm has been applied to study the following problems: one-dimensional flow through homogeneous media, steady-state and transient flow conditions, one-dimensional flow through heterogeneous media, steady-state and transient flow conditions, and two-dimensional steady-stte flow through heterogeneous media. The results are compared with those available in the literature.
Modeling Physical Quantities in Industrial Systems using Fluid Stochastic Petri Nets
Gribaudo, Marco
of a case study, in which the quantity to be regulated is a real fluid quantity: the fuel demand in a gas: Start Fuel Controller 2 Fluid Stochastic Petri Nets Fluid Stochastic Petri Nets are Petri net basedModeling Physical Quantities in Industrial Systems using Fluid Stochastic Petri Nets M. Gribaudo
Brinkmann Model and Double Penalization Method for the Flow Around a Porous Thin
Paris-Sud XI, Université de
the flow of a viscous fluid around a thin layer of porous material. Using a BKW method, we perform Keywords: Navier-Stokes equations, BKW method, penalization, porous ma- terial, thin layer. 1 Introduction are obtained with a BKW method. With these two asymptotic expansions, we will compare both models. We
Preliminary Analysis of Grande Ronde Basalt Formation Flow Top Transmissivity as it Relates to Assessment and Site Selection Applications for Fluid/Energy Storage and Sequestration Projects
Spane, Frank A.
Preliminary Analysis of Grande Ronde Basalt Formation Flow Top Transmissivity as it Relates to Assessment and Site Selection Applications for Fluid/Energy Storage and Sequestration Projects
Review and selection of unsaturated flow models
Reeves, M.; Baker, N.A.; Duguid, J.O. [INTERA, Inc., Las Vegas, NV (United States)
Since the 1960`s, ground-water flow models have been used for analysis of water resources problems. In the 1970`s, emphasis began to shift to analysis of waste management problems. This shift in emphasis was largely brought about by site selection activities for geologic repositories for disposal of high-level radioactive wastes. Model development during the 1970`s and well into the 1980`s focused primarily on saturated ground-water flow because geologic repositories in salt, basalt, granite, shale, and tuff were envisioned to be below the water table. Selection of the unsaturated zone at Yucca Mountain, Nevada, for potential disposal of waste began to shift model development toward unsaturated flow models. Under the US Department of Energy (DOE), the Civilian Radioactive Waste Management System Management and Operating Contractor (CRWMS M&O) has the responsibility to review, evaluate, and document existing computer models; to conduct performance assessments; and to develop performance assessment models, where necessary. This document describes the CRWMS M&O approach to model review and evaluation (Chapter 2), and the requirements for unsaturated flow models which are the bases for selection from among the current models (Chapter 3). Chapter 4 identifies existing models, and their characteristics. Through a detailed examination of characteristics, Chapter 5 presents the selection of models for testing. Chapter 6 discusses the testing and verification of selected models. Chapters 7 and 8 give conclusions and make recommendations, respectively. Chapter 9 records the major references for each of the models reviewed. Appendix A, a collection of technical reviews for each model, contains a more complete list of references. Finally, Appendix B characterizes the problems used for model testing.
Wind Turbine Modeling for Computational Fluid Dynamics: December 2010 - December 2012
Tossas, L. A. M.; Leonardi, S.
With the shortage of fossil fuel and the increasing environmental awareness, wind energy is becoming more and more important. As the market for wind energy grows, wind turbines and wind farms are becoming larger. Current utility-scale turbines extend a significant distance into the atmospheric boundary layer. Therefore, the interaction between the atmospheric boundary layer and the turbines and their wakes needs to be better understood. The turbulent wakes of upstream turbines affect the flow field of the turbines behind them, decreasing power production and increasing mechanical loading. With a better understanding of this type of flow, wind farm developers could plan better-performing, less maintenance-intensive wind farms. Simulating this flow using computational fluid dynamics is one important way to gain a better understanding of wind farm flows. In this study, we compare the performance of actuator disc and actuator line models in producing wind turbine wakes and the wake-turbine interaction between multiple turbines. We also examine parameters that affect the performance of these models, such as grid resolution, the use of a tip-loss correction, and the way in which the turbine force is projected onto the flow field.
Experimental and computational modeling of oscillatory flow within a baffled tube containing periodic-tri-orifice baffle geometries
Gomez, Hector
Experimental and computational modeling of oscillatory flow within a baffled tube containing describes numerical simulation and matching experimental results for oscillatory flow within a baffled tube the basic mechanism of OFM in a horizontal single-orifice baffled tube. As the fluid passes through
A model for transonic plasma flow
Guazzotto, Luca, E-mail: email@example.com [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)] [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Hameiri, Eliezer, E-mail: firstname.lastname@example.com [Courant Institute of Mathematical Sciences, New York University, New York, New York 10012 (United States)] [Courant Institute of Mathematical Sciences, New York University, New York, New York 10012 (United States)
A linear, two-dimensional model of a transonic plasma flow in equilibrium is constructed and given an explicit solution in the form of a complex Laplace integral. The solution indicates that the transonic state can be solved as an elliptic boundary value problem, as is done in the numerical code FLOW [Guazzotto et al., Phys. Plasmas 11, 604 (2004)]. Moreover, the presence of a hyperbolic region does not necessarily imply the presence of a discontinuity or any other singularity of the solution.
Internal Stress in a Model Elasto-Plastic Fluid
Takeshi Ooshida; Ken Sekimoto
Plastic materials can carry memory of past mechanical treatment in the form of internal stress. We introduce a natural definition of the vorticity of internal stress in a simple two-dimensional model of elasto-plastic fluids, which generates the internal stress. We demonstrate how the internal stress is induced under external loading, and how the presence of the internal stress modifies the plastic behavior.
Friedmann-like collapsing model of a radiating sphere with heat flow
Kolassis, C.A.; Santos, N.O.; Tsoubelis, D.
This paper considers a spherical body consisting of a fluid with heat flow which radiates in its exterior a null fluid described by the outgoing Vaidya's metric. A Friedmann-like exact solution of the interior Einstein field equations is given. It is proved that this solution, matched with the outgoing Vaidya matric, represents a physically reasonble collapsing model which, when the heat flow is switched off, reduces to the well-known collapsing model with dust. The proposed model has the remarkable property that even if the heat flow is small, the horizon will never be formed because, before this happens, the collapsing body will be destroyed by opposite gradients of pressure. 6 references.
A New Unified Dark Fluid Model and Its Cosmic Constraint
Xu, Lixin
In this paper, we propose a new unified dark fluid (UDF) model with equation of state (EoS) $w(a)=-\\alpha/(\\beta a^{-n}+1)$, which includes the generalized Chaplygin gas model (gGg) as its special case, where $\\alpha$, $\\beta$ and $n$ are three positive numbers. It is clear that this model reduces to the gCg model with EoS $w(a)=-B_s/(B_s+(1-B_s)a^{-3(1+\\alpha)})$, when $\\alpha=1$, $\\beta=(1-B_s)/B_s$ and $n=3(1+\\alpha)$. By combination the cold dark matter and the cosmological constant, one can coin a EoS of unified dark fluid in the form of $w(a)=-1/(1+(1-\\Omega_{\\Lambda})a^{-3}/\\Omega_{\\Lambda})$. With this observations, our proposed EoS provides a possible deviation from $\\Lambda$CDM model when the model parameters $\\alpha$ and $n$ deviate from 1 and 3 respectively. By using the currently available cosmic observations from type Ia supernovae (SN Ia) Union2.1, baryon acoustic oscillation (BAO) and cosmic microwave background radiation (CMB), we test the viability of this model and detect the possible devot...
Conductive and convective heat transfer in fluid flows between differentially heated and rotating cylinders
Lopez, Jose M; Avila, Marc
The flow of fluid confined between a heated rotating cylinder and a cooled stationary cylinder is a canonical experiment for the study of heat transfer in engineering. The theoretical treatment of this system is greatly simplified if the cylinders are assumed to be of infinite length or periodic in the axial direction, in which cases heat transfer occurs only through conduction as in a solid. We here investigate numerically heat transfer and the onset of turbulence in such flows by using both periodic and no-slip boundary conditions in the axial direction. We obtain a simple linear criterion that determines whether the infinite-cylinder assumption can be employed. The curvature of the cylinders enters this linear relationship through the slope and additive constant. For a given length-to-gap aspect ratio there is a critical Rayleigh number beyond which the laminar flow in the finite system is convective and so the behaviour is entirely different from the periodic case. The criterion does not depend on the Pra...
Measurement of fluid-flow-velocity profile in turbid media by the use of optical Doppler tomography
Wang, Xiao-Jun; Milner, T.E.; Chen, Zhongping; Nelson, J.S. [Beckman Laser Institute and Medical Clinic, University of California-Irvine, Irvine, California 92715 (United States)]|[Department of Physics, Georgia Southern University, Statesboro, Georgia 30460 (United States)
Optical Doppler tomography is demonstrated to be a simple, accurate, and noncontact method for measuring the fluid velocity of laminar flow in small-diameter ({approximately}0.5-mm) ducts. Studies are described that utilize circular (square) plastic (glass) ducts infused with a moving suspension of polymer micro-spheres in air and buried in an optically turbid medium. The measurement of Doppler-shifted frequencies of backscattered light from moving microspheres is used to construct a high-resolution spatial profile of fluid-flow velocity in the ducts. {copyright} 1997 Optical Society of America
A void distribution model-flashing flow
Riznic, J.; Ishii, M.; Afgan, N.
A new model for flashing flow based on wall nucleations is proposed here and the model predictions are compared with some experimental data. In order to calculate the bubble number density, the bubble number transport equation with a distributed source from the wall nucleation sites was used. Thus it was possible to avoid the usual assumption of a constant bubble number density. Comparisons of the model with the data shows that the model based on the nucleation site density correlation appears to be acceptable to describe the vapor generation in the flashing flow. For the limited data examined, the comparisons show rather satisfactory agreement without using a floating parameter to adjust the model. This result indicated that, at least for the experimental conditions considered here, the mechanistic predictions of the flashing phenomenon is possible on the present wall nucleation based model.
Experimental investigation of mixing in a stratified fluid due to diffusion-driven flows in a loosely-packed particle layer
Etheridge, William B. (William Bruce)
An experimental study was undertaken to investigate if a loosely-packed particle layer can induce mixing due to diffusion-driven Phillips-Wunsch boundary flows in a quiescent stratified fluid. Diffusion-driven flows can ...
Chaos control in traffic flow models
Elman Mohammed Shahverdiev; Shin-ichi Tadaki
Chaos control in some of the one- and two-dimensional traffic flow dynamical models in the mean field theory is studied.One dimensional model is investigated taking into account the effect of random delay. Two dimensional model takes into account the effects of overpasses, symmetric distribution of cars and blockages of cars moving in the same direction. Chaos synchronization is performed within both replica and nonreplica approaches, and using parameter perturbation method.
The conformation change of model polymers in stochastic flow fields: Flow through fixed beds
Shaqfeh, Eric
The conformation change of model polymers in stochastic flow fields: Flow through fixed beds Alisa that as a polymer solution flows through a fixed bed, the pressure drop neces- sary to pump the solution may
European Journal of Mechanics B/Fluids 25 (2006) 9871007 Wave propagation in a fluid flowing through
Pontrelli, Giuseppe
oscillatory flow has been considered in many studies. This work was initiated by Lyne [5] who used boundary-layer
Green Algae as Model Organisms for Biological Fluid Dynamics
Goldstein, Raymond E
In the past decade the volvocine green algae, spanning from the unicellular $Chlamydomonas$ to multicellular $Volvox$, have emerged as model organisms for a number of problems in biological fluid dynamics. These include flagellar propulsion, nutrient uptake by swimming organisms, hydrodynamic interactions mediated by walls, collective dynamics and transport within suspensions of microswimmers, the mechanism of phototaxis, and the stochastic dynamics of flagellar synchronization. Green algae are well suited to the study of such problems because of their range of sizes (from 10 $\\mu$m to several millimetres), their geometric regularity, the ease with which they can be cultured and the availability of many mutants that allow for connections between molecular details and organism-level behavior. This review summarizes these recent developments and highlights promising future directions in the study of biological fluid dynamics, especially in the context of evolutionary biology, that can take advantage of these re...
Green Algae as Model Organisms for Biological Fluid Dynamics
Raymond E. Goldstein
In the past decade the volvocine green algae, spanning from the unicellular $Chlamydomonas$ to multicellular $Volvox$, have emerged as model organisms for a number of problems in biological fluid dynamics. These include flagellar propulsion, nutrient uptake by swimming organisms, hydrodynamic interactions mediated by walls, collective dynamics and transport within suspensions of microswimmers, the mechanism of phototaxis, and the stochastic dynamics of flagellar synchronization. Green algae are well suited to the study of such problems because of their range of sizes (from 10 $\\mu$m to several millimetres), their geometric regularity, the ease with which they can be cultured and the availability of many mutants that allow for connections between molecular details and organism-level behavior. This review summarizes these recent developments and highlights promising future directions in the study of biological fluid dynamics, especially in the context of evolutionary biology, that can take advantage of these remarkable organisms.
MINET: transient analysis of fluid-flow and heat-transfer networks
Van Tuyle, G.J.; Guppy, J.G.; Nepsee, T.C.
MINET, a computer code developed for the steady-state and transient analysis of fluid-flow and heat-transfer networks, is described. The code is based on a momentum integral network method, which offers significant computational advantages in the analysis of large systems, such as the balance of plant in a power-generating facility. An application is discussed in which MINET is coupled to the Super System Code (SSC), an advanced generic code for the transient analysis of loop- or pool-type LMFBR systems. In this application, the ability of the Clinch River Breeder Reactor Plant to operate in a natural circulation mode following an assumed loss of all electric power, was assessed. Results from the MINET portion of the calculations are compared against those generated independently by the Clinch River Project, using the DEMO code.
The purpose of the saturated zone (SZ) flow and transport model abstraction task is to provide radionuclide-transport simulation results for use in the total system performance assessment (TSPA) for license application (LA) calculations. This task includes assessment of uncertainty in parameters that pertain to both groundwater flow and radionuclide transport in the models used for this purpose. This model report documents the following: (1) The SZ transport abstraction model, which consists of a set of radionuclide breakthrough curves at the accessible environment for use in the TSPA-LA simulations of radionuclide releases into the biosphere. These radionuclide breakthrough curves contain information on radionuclide-transport times through the SZ. (2) The SZ one-dimensional (I-D) transport model, which is incorporated in the TSPA-LA model to simulate the transport, decay, and ingrowth of radionuclide decay chains in the SZ. (3) The analysis of uncertainty in groundwater-flow and radionuclide-transport input parameters for the SZ transport abstraction model and the SZ 1-D transport model. (4) The analysis of the background concentration of alpha-emitting species in the groundwater of the SZ.
Microgravity Flow Regime Transition Modeling�
Shephard, Adam M.
................... 18 14 Colin and Fabre (1995) 0.0190 m diameter air-water data set ................... 18 15 Comparison of the Dukler et al. (1988) and Bousman (1994) 0.0127 m diameter air-water system data sets... ........................................................................................................ 67 33 Colin and Fabre (1995) 0.0190 m diameter air-water data set with models ........................................................................................................ 68 34 Dukler et al. (1988) 0.0127 m diameter air-water data...
Virtual Community Life Cycle: a Model to Develop Systems with Fluid Requirements Christo El Morr1
Paris-Sud XI, Universit� de
1 Virtual Community Life Cycle: a Model to Develop Systems with Fluid Requirements Christo El Morr1 into the life cycle model needed to develop information systems for group of people with fluid requirements development life cycles can be followed when developing any virtual community. Though, in a fluid environment
Multi-fluid Modeling of Transient a Case Study in the Generation and Guiding of Light
Eindhoven, Technische Universiteit
Multi-fluid Modeling of Transient Plasmas: a Case Study in the Generation and Guiding of Light, B.H.P. Multi-fluid Modeling of Transient Plasmas: a Case Study in the Generation and Guid- ing . . . . . . . . . . . . . . . . . . . . . . . . 37 2.3.1 The multi-fluid description in PLASIMO . . . . . . . . . . . . . . . . 38 iii #12;iv
Anderson, C.
FLUID DISPLACEMENT IN PETROLEUM RESERVOIRS C. Anderson andFLUID DISPLACEMENT IN PETROLEUM RESERVOIRS C. Anderson andachieve optimal recovery of petroleum from a reservoir, it
Fluid flow near reservoir lakes inferred from the spatial and temporal analysis of the electric potential
Adolphs, Ralph
, 2002. 1. Introduction [2] Detecting subsurface groundwater circulation using geophysical methods to result from the electrokinetic coupling associated with a vertical groundwater flow connecting a constant pore pressure source to the bottom of the lakes. Numerical modeling indicates that the spatial
CFD modeling of entrained-flow coal gasifiers with improved physical and chemical sub-models
Ma, J.; Zitney, S.
Optimization of an advanced coal-fired integrated gasification combined cycle system requires an accurate numerical prediction of gasifier performance. While the turbulent multiphase reacting flow inside entrained-flow gasifiers has been modeled through computational fluid dynamic (CFD), the accuracy of sub-models requires further improvement. Built upon a previously developed CFD model for entrained-flow gasification, the advanced physical and chemical sub-models presented here include a moisture vaporization model with consideration of high mass transfer rate, a coal devolatilization model with more species to represent coal volatiles and heating rate effect on volatile yield, and careful selection of global gas phase reaction kinetics. The enhanced CFD model is applied to simulate two typical oxygen-blown entrained-flow configurations including a single-stage down-fired gasifier and a two-stage up-fired gasifier. The CFD results are reasonable in terms of predicted carbon conversion, syngas exit temperature, and syngas exit composition. The predicted profiles of velocity, temperature, and species mole fractions inside the entrained-flow gasifier models show trends similar to those observed in a diffusion-type flame. The predicted distributions of mole fractions of major species inside both gasifiers can be explained by the heterogeneous combustion and gasification reactions and the homogeneous gas phase reactions. It was also found that the syngas compositions at the CFD model exits are not in chemical equilibrium, indicating the kinetics for both heterogeneous and gas phase homogeneous reactions are important. Overall, the results achieved here indicate that the gasifier models reported in this paper are reliable and accurate enough to be incorporated into process/CFD co-simulations of IGCC power plants for systemwide design and optimization.
The Product Flow Model Gio Wiederhold
Wiederhold, Gio
(IT) operations for software then little overall lifetime cost reduction has been achieved by reduced Boehm has demonstrated, a modest initial investment, say 20% over the most economical cost of deliveringThe Product Flow Model Gio Wiederhold Stanford University 14 May 2003 Abstract We observed a new
Efficient Production Optimization Using Flow Network Models
Lerlertpakdee, Pongsathorn
of the physical processes that govern the long-term behavior of the reservoir. We present an alternative solution that combines the advantages of both statistics-based and physics-based methods by deriving the flow predictions in complex two-dimensional models...
Grilli, Stéphan T.
approaches pursued were based on using : (i) linear or nonlinear Shallow Water Wave equations (Carrier approaches. Griffiths et al. 28 1992, compared measurements of internal kinematics of periodic waves shoalingCHAPTER NO. FULLY NONLINEAR POTENTIAL FLOW MODELS USED FOR LONG WAVE RUNUP PREDICTION (S. Grilli
Olufsen, Mette Sofie
MODELING BLOOD FLOW IN THE CARDIOVASCULAR SYSTEM MA432 � Spring 2013 Department of Mathematics (Greek),...; Two distinct types of blood were thought to exist: � "Nutritive blood" was thought to be made by the liver and carried through veins to the organs, where it was consumed � "Vital blood
Olufsen, Mette Sofie
MODELING BLOOD FLOW IN THE CARDIOVASCULAR SYSTEM MA325 � Spring 2013 Department of Mathematics (Greek),...; Two distinct types of blood were thought to exist: � Nutritive blood was thought to be made by the liver and carried through veins to the organs, where it was consumed � Vital blood was thought
of complex systems. A model of a nuclear power plant (PWR) is presented in the paper for illustration. Due SPECIFICATIONS 19 A MULTILEVEL FLOW MODEL OF A PWR 22 APPLICATIONS OF MULTILEVEL FLOW MODELS 24 ACKNOWLEDGEMENTS
One Time-step Finite Element Discretization of the Equation of Motion of Two-fluid Flows
Maury, Bertrand
obtained at each time step when dis- cretizing the lubricated transportation of heavy crude oil in a horizontal pipeline. In the petroleum industry, an efficient way for transporting heavy crude oil to the pipe wall and it surrounds the fluid with high viscosity (heavy oil). It is assumed that the flow
Stable stationary vortices and traveling oscillatory vortices in a stenotic fluid-flow channel David W. Pravica,1
Bier, Martin
will show that a sufficiently large boundary vor- ticity layer is required for stationary vortices and that a suf- ficiently high Reynolds number with a boundary shear stress is required for traveling oscillatoryStable stationary vortices and traveling oscillatory vortices in a stenotic fluid-flow channel
Determination of fluid viscosities from biconical annular geometries: Experimental and modeling studies
Rondon, Nolys Javier
Knowledge of viscosity of flow streams is essential for the design and operation of production facilities, drilling operations and reservoir engineering calculations. The determination of the viscosity of a reservoir fluid at downhole conditions...
Fluid Dynamics Models for Low Rank Discriminant Analysis Yung-Kyun Noh1,2
and velocity flow fields. We show how to apply the Gauss principle of least con- straint in fluids to obtain., 2000). Projection pursuit is a canonical approach to find a low dimen- sional subspace where
Unit physics performance of a mix model in Eulerian fluid computations
Vold, Erik [Los Alamos National Laboratory; Douglass, Rod [Los Alamos National Laboratory
In this report, we evaluate the performance of a K-L drag-buoyancy mix model, described in a reference study by Dimonte-Tipton [1] hereafter denoted as [D-T]. The model was implemented in an Eulerian multi-material AMR code, and the results are discussed here for a series of unit physics tests. The tests were chosen to calibrate the model coefficients against empirical data, principally from RT (Rayleigh-Taylor) and RM (Richtmyer-Meshkov) experiments, and the present results are compared to experiments and to results reported in [D-T]. Results show the Eulerian implementation of the mix model agrees well with expectations for test problems in which there is no convective flow of the mass averaged fluid, i.e., in RT mix or in the decay of homogeneous isotropic turbulence (HIT). In RM shock-driven mix, the mix layer moves through the Eulerian computational grid, and there are differences with the previous results computed in a Lagrange frame [D-T]. The differences are attributed to the mass averaged fluid motion and examined in detail. Shock and re-shock mix are not well matched simultaneously. Results are also presented and discussed regarding model sensitivity to coefficient values and to initial conditions (IC), grid convergence, and the generation of atomically mixed volume fractions.
Method and apparatus for balancing discharge fluid flow in drilling mud treatment units
Gay, C.J.
A method of controlling fluid flow in the drilling mud treatment units of an oil/gas well drilling rig such as, for example, the shale shaker, desander, desilter, and mud cleaner portions thereof provides floating the inlet of an intake conduit at the supernatent liquid layer of the drilling rig reserve pit and providing a common distributor head for routing the supernatent liquid to the various solid control units. A pump is connected to the intake conduit and the header at the intake and discharge respectively. The pump transmits the reserve pit supernatent from the reserve pit to the header by pumping. There is provided one or more branch lines affixed to the header each discharging respectively into the drain of a drilling mud treatment unit associated with the drilling rig with the flow of reserve pit supernatent liquid keeping the various drains open. The drains are positioned to discharge back into the reserve pit. The method saves the use of fresh water for the purpose of keeping drains open by the use of the supernatent liquid.
Global Stability Analysis of Fluid Flows using Sum-of-Squares
Jul 1, 2011 ... For finite dimensional approximations of fluid ...... if and only if there exist non-
Gamma-ray free-electron lasers: Quantum fluid model
Silva, H M
A quantum fluid model is used to describe the interacion of a nondegenerate cold relativistic electron beam with an intense optical wiggler taking into account the beam space-charge potential and photon recoil effect. A nonlinear set of coupled equations are obtained and solved numerically. The numerical results shows that in the limit of plasma wave-breaking an ultra-high power radiation pulse are emitted at the$\\gamma$-ray wavelength range which can reach an output intensity near the Schwinger limit depending of the values of the FEL parameters such as detuning and input signal initial phase at the entrance of the interaction region.
Kunzelman, K. S.; Einstein, Daniel R.; Cochran, R. P.
Successful mitral valve repair is dependent upon a full understanding of normal and abnormal mitral valve anatomy and function. Computational analysis is one such method that can be applied to simulate mitral valve function in order to analyze the roles of individual components, and evaluate proposed surgical repair. We developed the first three-dimensional, finite element (FE) computer model of the mitral valve including leaflets and chordae tendineae, however, one critical aspect that has been missing until the last few years was the evaluation of fluid flow, as coupled to the function of the mitral valve structure. We present here our latest results for normal function and specific pathologic changes using a fluid-structure interaction (FSI) model. Normal valve function was first assessed, followed by pathologic material changes in collagen fiber volume fraction, fiber stiffness, fiber splay, and isotropic stiffness. Leaflet and chordal stress and strain, and papillary muscle force was determined. In addition, transmitral flow, time to leaflet closure, and heart valve sound were assessed. Model predictions in the normal state agreed well with a wide range of available in-vivo and in-vitro data. Further, pathologic material changes that preserved the anisotropy of the valve leaflets were found to preserve valve function. By contrast, material changes that altered the anisotropy of the valve were found to profoundly alter valve function. The addition of blood flow and an experimentally driven microstructural description of mitral tissue represent significant advances in computational studies of the mitral valve, which allow further insight to be gained. This work is another building block in the foundation of a computational framework to aid in the refinement and development of a truly noninvasive diagnostic evaluation of the mitral valve. Ultimately, it represents the basis for simulation of surgical repair of pathologic valves in a clinical and educational setting.
Several applications of a model for dense granular flows
Cawthorn, Christopher John
model for the dense flow of dry granular materials (Jop, Forterre & Pouliquen, 2006, Nature, 441, 167-192). The model, based upon a generalisation of Coulomb sliding friction, is known to perform well when modelling certain simple free surface flows. We... such model was proposed by Savage & Hutter (1989), who accounted for simple Coulomb sliding friction at the base of the flow, and neglected internal stresses. This simple model, and its later generalisation to two-dimensional flows over complex topography...
A survey of air flow models for multizone structures
Feustel, H.E.; Dieris, J.
Air flow models are used to simulate the rates of incoming and outgoing air flows for a building with known leakage under given weather and shielding conditions. Additional information about the flow paths and air-mass flows inside the building can only by using multizone air flow models. In order to obtain more information on multizone air flow models, a literature review was performed in 1984. A second literature review and a questionnaire survey performed in 1989, revealed the existence of 50 multizone air flow models, all developed since 1966, two of which are still under development. All these programs use similar flow equations for crack flow but differ in the versatility to describe the full range of flow phenomena and the algorithm provided for solving the set of nonlinear equations. This literature review was found that newer models are able to describe and simulate the ventilation systems and interrelation of mechanical and natural ventilation. 27 refs., 2 figs., 1 tab.
Membrane filtration studies of inversely soluble model metalworking fluids
Misra, S.K.; Skoeld, R.O. [Chalmers Univ. of Technology, Gothenburg (Sweden)] [Chalmers Univ. of Technology, Gothenburg (Sweden)
Model metalworking fluids, characterized by phase separation of functional components at elevated temperatures, were studied. Results of membrane filtration experiments with three oils of differing chemical nature confirm the feasibility of specific removal of finely dispersed contaminant oils without the simultaneous loss of active components from adequately formulated fluids. Prerequisites are that membrane materials and pore sizes be suitably chosen and that operating temperatures be kept below the cloud point of the least soluble component. The most suitable filter in the present study was a hydrophilic regenerated cellulose membrane with a NMWL of 100,000 dalton. Complete oil removal was attained if membrane pore sizes did not exceed 0.1 {micro}m. It was also found that intrinsically water-soluble boundary lubricants of the polyglycol ether type are retained by membranes in the presence of PPG-1800, which serves as a precipitation promoter above the cloud point. This is of considerable practical importance since it offers the possibility of designing water-soluble boundary lubrication and extreme pressure additives which are activated by the presence of an inversely soluble component above its cloud point. The latter compound also acts as the principal hydrodynamic lubricant of the present model formulations. The usefulness of a new analytical tool for the rapid acquisition and imaging of data pertinent to changes in molecular aggregation and phase conditions was demonstrated.
Identification of fluid-flow paths in the Cerro Prieto geothermal field
Halfman, S.E.; Lippmann, M.J.; Zelwer, R.; Howard, J.H.
A hydrogeologic model of the Cerro Prieto geothermal field has been developed based on geophysical and lithologic well logs, downhole temperature, and well completion data from about 90 deep wells. The hot brines seem to originate in the eastern part of the field, flowing in a westward direction and rising through gaps in the shaly layers which otherwise act as partial caprocks to the geothermal resource.
RELAP5 subcooled critical flow model verification
Petelin, S.; Gortnar, O.; Mavko, B. (Institut Jozef Stefan, Ljubljana (Solomon Islands))
We discuss some results of the RELAP5 break modeling during the analysis of International Standard Problem 27 (ISP-27) performed on the BETHSY facility. This study deals with the discontinuity of the RELAP5 critical flow prediction in a strongly subcooled region. Such unrealistic behavior was observed during the pretest simulations of ISP-27. Based on the investigation, a RELAP5 code correction is suggested that ensures a more appropriate simulation of the critical discharge of strongly subcooled liquid.
Abdou, Mohamed
NUMERICAL MODELING FOR MULTIPHASE INCOMPRESSIBLE FLOW WITH PHASE CHANGE Xiao-Yong Luo, Ming-Jiu Ni for multiphase flows. A con- tinuum surface force (CSF) tension model is used in the present cases. Phase change
Numerical modeling of the elution peak profiles of retained solutes in supercritical fluid chromatography
Kaczmarski, Krzysztof [University of Tennessee and Rzeszow University of Technology, Poland; Guiochon, Georges A [ORNL
In supercritical fluid chromatography (SFC), the significant expansion of the mobile phase along the column causes the formation of axial and radial gradients of temperature. Due to these gradients, the mobile phase density, its viscosity, its velocity, its diffusion coefficients, etc. are not constant throughout the column. This results in a nonuniform flow velocity distribution, itself causing a loss of column efficiency in certain cases, even at low flow rates, as they do in HPLC. At high flow rates, an important deformation of the elution profiles of the sample components may occur. The model previously used to account satisfactorily for the retention of an unsorbed solute in SFC is applied to the modeling of the elution peak profiles of retained compounds. The numerical solution of the combined heat and mass balance equations provides the temperature and the pressure profiles inside the column and values of the retention time and the band profiles of retained compounds that are in excellent agreement with independent experimental data for large value of mobile phase reduced density. At low reduced densities, the band profiles can strongly depend on the column axial distribution of porosity.
Review and selection of unsaturated flow models
Under the US Department of Energy (DOE), the Civilian Radioactive Waste Management System Management and Operating Contractor (CRWMS M&O) has the responsibility to review, evaluate, and document existing computer ground-water flow models; to conduct performance assessments; and to develop performance assessment models, where necessary. In the area of scientific modeling, the M&O CRWMS has the following responsibilities: To provide overall management and integration of modeling activities. To provide a framework for focusing modeling and model development. To identify areas that require increased or decreased emphasis. To ensure that the tools necessary to conduct performance assessment are available. These responsibilities are being initiated through a three-step process. It consists of a thorough review of existing models, testing of models which best fit the established requirements, and making recommendations for future development that should be conducted. Future model enhancement will then focus on the models selected during this activity. Furthermore, in order to manage future model development, particularly in those areas requiring substantial enhancement, the three-step process will be updated and reported periodically in the future.
Application of Multi-rate Flowing Fluid Electric ConductivityLogging Method to Well DH-2, Tono Site, Japan
Doughty, Christine; Takeuchi, Shinji; Amano, Kenji; Shimo, Michito; Tsang, Chin-Fu
The flowing fluid electric conductivity (FEC) logging method, wellbore fluid is replaced with de-ionized water, following which FEC profiles in the wellbore are measured at a series of times while the well is pumped at a constant rate. Locations were fluid enters the wellbore show peaks in the FEC logs, which may be analyzed to infer inflow strengths and salinities of permeable features intersected by the wellbore. In multi-rate flowing FEC logging, the flowing FEC logging method is repeated using two or more pumping rates, which enables the transmissivities and inherent pressure heads of these features to be estimated as well. We perform multi-rate FEC logging on a deep borehole in fractured granitic rock, using three different pumping rates. Results identify 19 hydraulically conducting fractures and indicate that transmissivity, pressure head, and salinity vary significantly among them. By using three pumping rates rather than the minimum number of two, we obtain an internal consistency check on the analysis that provides a measure of the uncertainty of the results. Good comparisons against static FEC profiles and against independent chemical, geological, and hydrogeological data have further enhanced confidence in the results of the multi-rate flowing FEC logging method.
A modeling approach for analysis of coupled multiphase fluid flow ...
enhanced recovery from oil and gas reservoirs, and underground storage of natural gas. Recently, under- ... empirical exponent for aperture versus normal stress function (1/Pa). Dv ..... are then used to derive new strain rates and stress, which.
Radiation Modeling In Fluid Flow Iain D. Boyd
Wang, Wei
Collector #12;4 Fundamentals of Radiation (1) � All matter with non-zero temperature emits thermal radiation with energy flux given by the Stefan-Boltzmann Law: e.g., Sun: T=5800 K, total radiated power = 4 distribution (Planck spectrum) !q =T 4 W/m2 #12;5 Planck Radiation Spectrum #12;6 Solar Radiation Spectrum
Abstract. CO2 sequestration in the underground is a valid alternative approach for mitigat- ing the greenhouse effect. Nevertheless, very little is known about the
Numerical modeling of fluid flow and time-lapse seismograms ...
(greenhouse effect). � To minimize climate change impacts, geological sequestration of CO2 is an immediate option. � Geologic sequestration involves injecting�...
Monitoring and Modeling Fluid Flow in a Developing Enhanced Geothermal...
Broader source: Energy.gov (indexed) [DOE]
Program Peer Review Report DOE 2010 Geothermal Technologies Program Peer Review seismic025fehler.pdf More Documents & Publications Analysis of Geothermal Reservoir...
Monitoring and Modeling Fluid Flow in a Developing EGS
Broader source: Energy.gov (indexed) [DOE]
well constrained are depths of the events? How well can we do with a relatively sparse seismic network located on the surface (typical EGS monitoring) RelevanceImpact of Research...
Can We Accurately Model Fluid Flow in Shale?
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisiting the TWPSuccess StoriesFebruary 26,Computers »CafeteriasTours SHAREU.S.Can We
Can We Accurately Model Fluid Flow in Shale?
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisiting the TWPSuccess StoriesFebruary 26,Computers »CafeteriasTours SHAREU.S.Can
Fluid Flow Model Development for Representative Geologic Media | Department
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport inEnergy0.pdf Flash2010-60.pdf2 DOE Hydrogen and FuelFloridaof Energy
Imaging, Characterizing, and Modeling of Fracture Networks and Fluid Flow
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(Fact Sheet),Energy Petroleum TechnologyEnergyImaging Ahead ofin EGS
Imaging, Characterizing, and Modeling of Fracture Networks and Fluid Flow
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(Fact Sheet),Energy Petroleum TechnologyEnergyImaging Ahead ofin EGSin EGS
Stocker, H.
Flow in Central High Energy Nuclear Collisions H. Stockera,theoretical models of high energy nuclear collisions andunder Contract High energy nuclear collisions offer a unique
A thin film model for corotational Jeffreys fluids under strong slip
A. M�nch; B. Wagner; M. Rauscher; R. Blossey
We derive a thin film model for viscoelastic liquids under strong slip which obey the stress tensor dynamics of corotational Jeffreys fluids.
Physical Model Development and Benchmarking for MHD Flows in Blanket Design
Ramakanth Munipalli; P.-Y.Huang; C.Chandler; C.Rowell; M.-J.Ni; N.Morley; S.Smolentsev; M.Abdou
An advanced simulation environment to model incompressible MHD flows relevant to blanket conditions in fusion reactors has been developed at HyPerComp in research collaboration with TEXCEL. The goals of this phase-II project are two-fold: The first is the incorporation of crucial physical phenomena such as induced magnetic field modeling, and extending the capabilities beyond fluid flow prediction to model heat transfer with natural convection and mass transfer including tritium transport and permeation. The second is the design of a sequence of benchmark tests to establish code competence for several classes of physical phenomena in isolation as well as in select (termed here as �canonical�,) combinations. No previous attempts to develop such a comprehensive MHD modeling capability exist in the literature, and this study represents essentially uncharted territory. During the course of this Phase-II project, a significant breakthrough was achieved in modeling liquid metal flows at high Hartmann numbers. We developed a unique mathematical technique to accurately compute the fluid flow in complex geometries at extremely high Hartmann numbers (10,000 and greater), thus extending the state of the art of liquid metal MHD modeling relevant to fusion reactors at the present time. These developments have been published in noted international journals. A sequence of theoretical and experimental results was used to verify and validate the results obtained. The code was applied to a complete DCLL module simulation study with promising results.
Computational Fluid Dynamics Modeling of the John Day Dam Tailrace
Rakowski, Cynthia L.; Perkins, William A.; Richmond, Marshall C.; Serkowski, John A.
US Army Corps of Engineers - Portland District required that a two-dimensional (2D) depth-averaged and a three-dimensional (3D) free-surface numerical models to be developed and validated for the John Day tailrace. These models were used to assess potential impact of a select group of structural and operational alternatives to tailrace flows aimed at improving fish survival at John Day Dam. The 2D model was used for the initial assessment of the alternatives in conjunction with a reduced-scale physical model of the John Day Project. A finer resolution 3D model was used to more accurately model the details of flow in the stilling basin and near-project tailrace hydraulics. Three-dimensional model results were used as input to the Pacific Northwest National Laboratory particle tracking software, and particle paths and times to pass a downstream cross section were used to assess the relative differences in travel times resulting from project operations and structural scenarios for multiple total river flows. Streamlines and neutrally-buoyant particles were seeded in all turbine and spill bays with flows. For a Total River of 250 kcfs running with the Fish Passage Plan spill pattern and a spillwall, the mean residence times for all particles were little changed; however the tails of the distribution were truncated for both spillway and powerhouse release points, and, for the powerhouse releases, reduced the residence time for 75% of the particles to pass a downstream cross section from 45.5 minutes to 41.3 minutes. For a total river of 125 kcfs configured with the operations from the Fish Passage Plan for the temporary spillway weirs and for a proposed spillwall, the neutrally-buoyant particle tracking data showed that the river with a spillwall in place had the overall mean residence time increase; however, the residence time for 75% of the powerhouse-released particles to pass a downstream cross section was reduced from 102.4 min to 89 minutes.
Fluid Queue Models of Renewable Energy Storage Gareth L. Jones and Peter G. Harrison
Imperial College, London
in a small example describing the delivery of renewable power to consumers. To model networks more accuratelyFluid Queue Models of Renewable Energy Storage Gareth L. Jones and Peter G. Harrison Department of networks of fluid queues. Such models can be used to describe the generation and storage of renewable
Stochastic models of Lagrangian acceleration of fluid particle in developed turbulence
A. K. Aringazin; M. I. Mazhitov
Modeling statistical properties of motion of a Lagrangian particle advected by a high-Reynolds-number flow is of much practical interest and complement traditional studies of turbulence made in Eulerian framework. The strong and nonlocal character of Lagrangian particle coupling due to pressure effects makes the main obstacle to derive turbulence statistics from the three-dimensional Navier-Stokes equation; motion of a single fluid-particle is strongly correlated to that of the other particles. Recent breakthrough Lagrangian experiments with high resolution of Kolmogorov scale have motivated growing interest to acceleration of a fluid particle. Experimental stationary statistics of Lagrangian acceleration conditioned on Lagrangian velocity reveals essential dependence of the acceleration variance upon the velocity. This is confirmed by direct numerical simulations. Lagrangian intermittency is considerably stronger than the Eulerian one. Statistics of Lagrangian acceleration depends on Reynolds number. In this review we present description of new simple models of Lagrangian acceleration that enable data analysis and some advance in phenomenological study of the Lagrangian single-particle dynamics. Simple Lagrangian stochastic modeling by Langevin-type dynamical equations is one the widely used tools. The models are aimed particularly to describe the observed highly non-Gaussian conditional and unconditional acceleration distributions. Stochastic one-dimensional toy models capture main features of the observed stationary statistics of acceleration. We review various models and focus in a more detail on the model which has some deductive support from the Navier-Stokes equation. Comparative analysis on the basis of the experimental data and direct numerical simulations is made.
Elliptic Flow from a Hybrid CGC, Full 3D Hydro and Hadronic Cascade Model
Tetsufumi Hirano; Ulrich W. Heinz; Dmitri Kharzeev; Roy Lacey; Yasushi Nara
We investigate the robustness of the discovery of the perfect fluid through comparison of hydrodynamic calculations with the elliptic flow coefficient v_2 at midrapidity in Au+Au collisions at sqrt{s_{NN}}=200 GeV. Employing the Glauber model for initial entropy density distributions, the centrality dependence of v_2 is reasonably reproduced by using an ideal fluid description of the early QGP stage followed by a hadronic cascade in the late hadronic stage. On the other hand, initial conditions based on the Colour Glass Condensate model are found to generate larger elliptic flow due to larger initial eccentricity epsilon. We further predict v_2/epsilon at a fixed impact parameter as a function of collision energy sqrt{s_{NN}} up to the LHC energy.
Pajarito Plateau Groundwater Flow and Transport Modeling Process-Level and Systems Models of Groundwater Flow and
Lu, Zhiming
Pajarito Plateau Groundwater Flow and Transport Modeling 1 Process-Level and Systems Models of Groundwater Flow and Transport Beneath the Pajarito Plateau: Migration of High Explosives from Technical Area Groundwater Modeling Project Systems Model Vadose Zone Model Regional Aquifer Model #12;Pajarito Plateau
Robert Podgorney; Chuan Lu; Hai Huang
Development of enhanced geothermal systems (EGS) will require creation of a reservoir of sufficient volume to enable commercial-scale heat transfer from the reservoir rocks to the working fluid. A key assumption associated with reservoir creation/stimulation is that sufficient rock volumes can be hydraulically fractured via both tensile and shear failure, and more importantly by reactivation of naturally existing fractures (by shearing), to create the reservoir. The advancement of EGS greatly depends on our understanding of the dynamics of the intimately coupled rock-fracture-fluid-heat system and our ability to reliably predict how reservoirs behave under stimulation and production. Reliable performance predictions of EGS reservoirs require accurate and robust modeling for strongly coupled thermal-hydrological-mechanical (THM) processes. Conventionally, these types of problems have been solved using operator-splitting methods, usually by coupling a subsurface flow and heat transport simulators with a solid mechanics simulator via input files. An alternative approach is to solve the system of nonlinear partial differential equations that govern multiphase fluid flow, heat transport, and rock mechanics simultaneously, using a fully coupled, fully implicit solution procedure, in which all solution variables (pressure, enthalpy, and rock displacement fields) are solved simultaneously. This paper describes numerical simulations used to investigate the poro- and thermal- elastic effects of working fluid injection and thermal energy extraction on the properties of the fractures and rock matrix of a hypothetical EGS reservoir, using a novel simulation software FALCON (Podgorney et al., 2011), a finite element based simulator solving fully coupled multiphase fluid flow, heat transport, rock deformation, and fracturing using a global implicit approach. Investigations are also conducted on how these poro- and thermal-elastic effects are related to fracture permeability evolution.
264 Solutions Manual x Fluid Mechanics, Fifth Edition Solution: (a) Write the steady flow energy equation from top to bottom
Bahrami, Majid
exiting the tube is negligible because of the low velocity (0.36 m/s). 3.139 The horizontal pump in Fig. P264 Solutions Manual x Fluid Mechanics, Fifth Edition Solution: (a) Write the steady flow energy g g ggd D D P D U U U Noting that, in a tube, Q VSd2/4, we may eliminate V in favor of Q
Observing and modeling Earths energy flows
Stevens B.; Schwartz S.
This article reviews, from the authors perspective, progress in observing and modeling energy flows in Earth's climate system. Emphasis is placed on the state of understanding of Earth's energy flows and their susceptibility to perturbations, with particular emphasis on the roles of clouds and aerosols. More accurate measurements of the total solar irradiance and the rate of change of ocean enthalpy help constrain individual components of the energy budget at the top of the atmosphere to within {+-}2 W m{sup -2}. The measurements demonstrate that Earth reflects substantially less solar radiation and emits more terrestrial radiation than was believed even a decade ago. Active remote sensing is helping to constrain the surface energy budget, but new estimates of downwelling surface irradiance that benefit from such methods are proving difficult to reconcile with existing precipitation climatologies. Overall, the energy budget at the surface is much more uncertain than at the top of the atmosphere. A decade of high-precision measurements of the energy budget at the top of the atmosphere is providing new opportunities to track Earth's energy flows on timescales ranging from days to years, and at very high spatial resolution. The measurements show that the principal limitation in the estimate of secular trends now lies in the natural variability of the Earth system itself. The forcing-feedback-response framework, which has developed to understand how changes in Earth's energy flows affect surface temperature, is reviewed in light of recent work that shows fast responses (adjustments) of the system are central to the definition of the effective forcing that results from a change in atmospheric composition. In many cases, the adjustment, rather than the characterization of the compositional perturbation (associated, for instance, with changing greenhouse gas concentrations, or aerosol burdens), limits accurate determination of the radiative forcing. Changes in clouds contribute importantly to this adjustment and thus contribute both to uncertainty in estimates of radiative forcing and to uncertainty in the response. Models are indispensable to calculation of the adjustment of the system to a compositional change but are known to be flawed in their representation of clouds. Advances in tracking Earth's energy flows and compositional changes on daily through decadal timescales are shown to provide both a critical and constructive framework for advancing model development and evaluation.
Numerical modeling of carrier gas flow in atomic layer deposition vacuum reactor: A comparative study of lattice Boltzmann models
Pan, Dongqing; Chien Jen, Tien [Department of Mechanical Engineering, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201 (United States); Li, Tao [School of Mechanical Engineering, Dalian University of Technology, Dalian 116024 (China); Yuan, Chris, E-mail: email@example.com [Department of Mechanical Engineering, University of Wisconsin-Milwaukee, 3200 North Cramer Street, Milwaukee, Wisconsin 53211 (United States)
This paper characterizes the carrier gas flow in the atomic layer deposition (ALD) vacuum reactor by introducing Lattice Boltzmann Method (LBM) to the ALD simulation through a comparative study of two LBM models. Numerical models of gas flow are constructed and implemented in two-dimensional geometry based on lattice Bhatnagar�Gross�Krook (LBGK)-D2Q9 model and two-relaxation-time (TRT) model. Both incompressible and compressible scenarios are simulated and the two models are compared in the aspects of flow features, stability, and efficiency. Our simulation outcome reveals that, for our specific ALD vacuum reactor, TRT model generates better steady laminar flow features all over the domain with better stability and reliability than LBGK-D2Q9 model especially when considering the compressible effects of the gas flow. The LBM-TRT is verified indirectly by comparing the numerical result with conventional continuum-based computational fluid dynamics solvers, and it shows very good agreement with these conventional methods. The velocity field of carrier gas flow through ALD vacuum reactor was characterized by LBM-TRT model finally. The flow in ALD is in a laminar steady state with velocity concentrated at the corners and around the wafer. The effects of flow fields on precursor distributions, surface absorptions, and surface reactions are discussed in detail. Steady and evenly distributed velocity field contribute to higher precursor concentration near the wafer and relatively lower particle velocities help to achieve better surface adsorption and deposition. The ALD reactor geometry needs to be considered carefully if a steady and laminar flow field around the wafer and better surface deposition are desired.
CCM Continuity Constraint Method: A finite-element computational fluid dynamics algorithm for incompressible Navier-Stokes fluid flows
Williams, P.T.
As the field of computational fluid dynamics (CFD) continues to mature, algorithms are required to exploit the most recent advances in approximation theory, numerical mathematics, computing architectures, and hardware. Meeting this requirement is particularly challenging in incompressible fluid mechanics, where primitive-variable CFD formulations that are robust, while also accurate and efficient in three dimensions, remain an elusive goal. This dissertation asserts that one key to accomplishing this goal is recognition of the dual role assumed by the pressure, i.e., a mechanism for instantaneously enforcing conservation of mass and a force in the mechanical balance law for conservation of momentum. Proving this assertion has motivated the development of a new, primitive-variable, incompressible, CFD algorithm called the Continuity Constraint Method (CCM). The theoretical basis for the CCM consists of a finite-element spatial semi-discretization of a Galerkin weak statement, equal-order interpolation for all state-variables, a 0-implicit time-integration scheme, and a quasi-Newton iterative procedure extended by a Taylor Weak Statement (TWS) formulation for dispersion error control. Original contributions to algorithmic theory include: (a) formulation of the unsteady evolution of the divergence error, (b) investigation of the role of non-smoothness in the discretized continuity-constraint function, (c) development of a uniformly H{sup 1} Galerkin weak statement for the Reynolds-averaged Navier-Stokes pressure Poisson equation, (d) derivation of physically and numerically well-posed boundary conditions, and (e) investigation of sparse data structures and iterative methods for solving the matrix algebra statements generated by the algorithm.
Diffusion driven object propulsion in density stratified fluids
Lenahan, Conor (Conor P.)
An experimental study was conducted in order to verify the appropriateness of a two dimensional model of the flow creating diffusion driven object propulsion in density stratified fluids. Initial flow field experiments ...
Potential Flow Modelling for Wind Turbines Shane Cline
Victoria, University of
Potential Flow Modelling for Wind Turbines by Shane Cline B.Sc., University of Toledo, 2003 M means, without the permission of the author. #12;ii Potential Flow Modelling for Wind Turbines by Shane potential flow methods are a promising alternative to mainstream wind turbine aerodynamics tools
Forebay Computational Fluid Dynamics Modeling for The Dalles Dam to Support Vortex Suppress Device Studies
Rakowski, Cynthia L.; Richmond, Marshall C.; Serkowski, John A.
A computational fluid dynamics (CFD) model was used in an investigation into the suppression of a surface vortex that forms and the south-most spilling bay at The Dalles Project. The CFD work complemented work at the prototype and the reduced-scale physical models. The CFD model was based on a model developed for other work in the forebay but had additional resolution added near the spillway. Vortex suppression devices (VSDs) were to placed between pier noses and/or in the bulkhead slot of the spillway bays. The simulations in this study showed that placing VSD structures or a combination of structures to suppress the vortex would still result in near-surface flows to be entrained in a vortex near the downstream spillwall. These results were supported by physical model and prototype studies. However, there was a consensus of the fish biologists at the physical model that the fish would most likely move north and if the fish went under the VSD it would immediately exit the forebay through the tainter gate and not get trapped between VSDs or the VSDs and the tainter gate if the VSDs were deep enough.
Uncertainty quantification in reacting flow modeling.
Le Ma�itre, Olivier P. (Universit�e d'Evry Val d'Essonne, Evry, France); Reagan, Matthew T.; Knio, Omar M. (Johns Hopkins University, Baltimore, MD); Ghanem, Roger Georges (Johns Hopkins University, Baltimore, MD); Najm, Habib N.
Uncertainty quantification (UQ) in the computational modeling of physical systems is important for scientific investigation, engineering design, and model validation. In this work we develop techniques for UQ based on spectral and pseudo-spectral polynomial chaos (PC) expansions, and we apply these constructions in computations of reacting flow. We develop and compare both intrusive and non-intrusive spectral PC techniques. In the intrusive construction, the deterministic model equations are reformulated using Galerkin projection into a set of equations for the time evolution of the field variable PC expansion mode strengths. The mode strengths relate specific parametric uncertainties to their effects on model outputs. The non-intrusive construction uses sampling of many realizations of the original deterministic model, and projects the resulting statistics onto the PC modes, arriving at the PC expansions of the model outputs. We investigate and discuss the strengths and weaknesses of each approach, and identify their utility under different conditions. We also outline areas where ongoing and future research are needed to address challenges with both approaches.
Fluid computation of the performanceenergy trade-off in large scale Markov models
Imperial College, London
Fluid computation of the performanceenergy trade-off in large scale Markov models Anton Stefanek energy consumption while maintaining multiple service level agreements. 2. VIRTUALISED EXECUTION MODEL optimisation. We show how the fluid analysis naturally leads to a constrained global optimisation prob- lem
Stochastic and deterministic models for dense granular flow
Kamrin, Kenneth Norman
Granular materials such as sand or gravel surround us everyday and yet remain poorly understood. In this thesis, two models are developed for dense granular flow, each capable of predicting flows with accuracy in multiple ...
Dissolution-induced surface modifications and permeability changes associated with fluid flow through an abraded saw-cut in single crystal quartz�
Bowman, James Albert
DISSOLUTION-INDUCED SURFACE MODIFICATIONS AND PERMEABILITY CHANGES ASSOCIATED WITH FLUID FLOW THROUGH AN ABRADED SAW-CUT IN SINGLE CRYSTAL QUARTZ A Thesis by JAlvlES ALBERT BOWMAN, JR, Submined to the Oflice of Graduate Studies of Texas A8r...M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Xiay I992 Major Subject: Geology DISSOLUTION-INDUCED SURFACE MODIFICATIONS AND PERMEABILITY CHANGES ASSOCIATED WITH FLUID FLOW THROUGH AN ABRADED SAW...
Modeling flow in a pressure-sensitive, heterogeneous medium
Vasco, Donald W.
deformation modeling, J. of Petrol. Sci. and Eng. , 38, 37-sandstone reservoir rocks, J. Petrol. Tech. , March, 15-16.fluid properties, Soc. Petrol. Eng. J. ,, 267-276. Rickett,
One-dimensional fluid diffusion induced by constant-rate flow injection: Theoretical analysis and application
is essential in the exploitation of natural fluid resources, such as water, steam, petroleum, and natural gas advantages of our method are the reliability of the testing method, its economy of time, and the flexibility wastes. [3] In general, the nature of fluids in reservoir rocks can be characterized in terms of quantity
Statistical Estimation of Fluid Flow Fields Johnny Chang David Edwards Yizhou Yu
Yu, Yizhou
their motion fields. 1 Introduction Dynamic fluids, such as rivers, ocean waves, moving clouds, smoke and fires (4) where is the kinematic viscosity of the fluid, is its den- sity and f is an external force scale. A good ex- ample is the changing surface geometry of a water surface. This is because the self
A Penalty Method to Model Particle Interactions in DNA-laden Flows
Trebotich, D; Miller, G H; Bybee, M D
We present a hybrid fluid-particle algorithm to simulate flow and transport of DNA-laden fluids in microdevices. Relevant length scales in microfluidic systems range from characteristic channel sizes of millimeters to micron scale geometric variation (e.g., post arrays) to 10 nanometers for the length of a single rod in a bead-rod polymer representation of a biological material such as DNA. The method is based on a previous fluid-particle algorithm in which long molecules are represented as a chain of connected rods, but in which the physically unrealistic behavior of rod crossing occurred. We have extended this algorithm to include screened Coulombic forces between particles by implementing a Debye-Hueckel potential acting between rods. In the method an unsteady incompressible Newtonian fluid is discretized with a second-order finite difference method in the interior of the Cartesian grid domain; an embedded boundary volume-of-fluid formulation is used near boundaries. The bead-rod polymer model is fully coupled to the solvent through body forces representing hydrodynamic drag and stochastic thermal fluctuations. While intrapolymer interactions are modeled by a soft potential, polymer-structure interactions are treated as perfectly elastic collisions. We demonstrate this method on flow and transport of a polymer through a post array microchannel in 2D where the polymer incorporates more realistic physical parameters of DNA, and compare to previous simulations where rods are allowed to cross. We also show that the method is capable of simulating 3D flow in a packed bed micro-column.
Swirling structure for mixing two concentric fluid flows at nozzle outlet
Mensink, Daniel L. (3578 Gregory La., Lynchburg, VA 24503)
A nozzle device for causing two fluids to mix together. In particular, a spray nozzle comprise two hollow, concentric housings, an inner housing and an outer housing. The inner housing has a channel formed therethrough for a first fluid. Its outer surface cooperates with the interior surface of the outer housing to define the second channel for a second fluid. The outer surface of the inner housing and the inner surface of the outer housing each carry a plurality of vanes that interleave but do not touch, each vane of one housing being between two vanes of the other housing. The vanes are curved and the inner surface of the outer housing and the outer surface of the inner housing converge to narrow the second channel. The shape of second channel results in a swirling, accelerating second fluid that will impact the first fluid just past the end of the nozzle where mixing will take place.
A Kinetic-Fluid Model C. Z. Cheng and Jay R. Johnson
A Kinetic-Fluid Model C. Z. Cheng and Jay R. Johnson Princeton University, Plasma Physics developed a kinetic-MHD model [Cheng, 1991] to study particle kinetic eects on MHD phenomena by taking
A KineticFluid Model C. Z. Cheng and Jay R. Johnson
A KineticFluid Model C. Z. Cheng and Jay R. Johnson Princeton University, Plasma Physics have previously developed a kineticMHD model [Cheng, 1991] to study particle kinetic effects on MHD
Inviscid Limits for a Stochastically Forced Shell Model of Turbulent Flow
Susan Friedlander; Nathan Glatt-Holtz; Vlad Vicol
We establish the anomalous mean dissipation rate of energy in the inviscid limit for a stochastic shell model of turbulent fluid flow. The proof relies on viscosity independent bounds for stationary solutions and on establishing ergodic and mixing properties for the viscous model. The shell model is subject to a degenerate stochastic forcing in the sense that noise acts directly only through one wavenumber. We show that it is hypo-elliptic (in the sense of Hormander) and use this property to prove a gradient bound on the Markov semigroup.
Elliptic flow fluctuations in heavy ion collisions at RHIC and the perfect fluid hypothesis
Sascha Vogel; Giorgio Torrieri; Marcus Bleicher
We analyse the recently measured $v_2$ fluctuation in the context of establishing the degree of fluidity of the matter produced in heavy ion collisions. We argue that flow observables within systems with a non-negligible mean free path should acquire a "dynamical" fluctuation, due to the random nature of each collision between the system's degrees of freedom. Because of this, $v_2$ fluctuations can be used to estimate the Knudsen number of the system produced at RHIC. To illustrate this quantitatively, we apply the UrQMD model, with scaled cross sections, to show that collisions at RHIC have a Knudsen number at least one order of magnitude above the expected value for an interacting hadron gas. Furthermore, we argue that the Knudsen number is also bound from above by the $v_2$ fluctuation data, because too large a Knudsen number would break the observed scaling of $v_2$ fluctuations due to the onset of turbulent flow. We propose, therefore that $v_2$ fluctuation measurements, together with an understanding of the turbulent regime for relativistic hydrodynamics, will provide an upper as well as a lower limit for the Knudsen number.
Unbounded dynamics in dissipative flows: R�ssler model
Barrio, Roberto, E-mail: firstname.lastname@example.com; Serrano, Sergio, E-mail: firstname.lastname@example.com [Computational Dynamics Group, Dpto. Matem�tica Aplicada and IUMA, Universidad de Zaragoza, E-50009 Zaragoza (Spain)] [Computational Dynamics Group, Dpto. Matem�tica Aplicada and IUMA, Universidad de Zaragoza, E-50009 Zaragoza (Spain); Blesa, Fernando, E-mail: email@example.com [Computational Dynamics Group, Dpto. F�sica Aplicada and IUMA, Universidad de Zaragoza, E-50009 Zaragoza (Spain)] [Computational Dynamics Group, Dpto. F�sica Aplicada and IUMA, Universidad de Zaragoza, E-50009 Zaragoza (Spain)
Transient chaos and unbounded dynamics are two outstanding phenomena that dominate in chaotic systems with large regions of positive and negative divergences. Here, we investigate the mechanism that leads the unbounded dynamics to be the dominant behavior in a dissipative flow. We describe in detail the particular case of boundary crisis related to the generation of unbounded dynamics. The mechanism of the creation of this crisis in flows is related to the existence of an unstable focus-node (or a saddle-focus) equilibrium point and the crossing of a chaotic invariant set of the system with the weak-(un)stable manifold of the equilibrium point. This behavior is illustrated in the well-known R�ssler model. The numerical analysis of the system combines different techniques as chaos indicators, the numerical computation of the bounded regions, and bifurcation analysis. For large values of the parameters, the system is studied by means of Fenichel's theory, providing formulas for computing the slow manifold which influences the evolution of the first stages of the orbit.
Evolution of elliptic and triangular flow as a function of collision energy in a hybrid model
Jussi Auvinen; Hannah Petersen
We study the collision energy dependence of elliptic flow v_2 and triangular flow v_3 in Au+Au collisions within the energy range sqrt(s_{NN}) = 5-200 GeV, utilizing a transport + hydrodynamics hybrid model. The transport part is described by the Ultrarelativistic Quantum Molecular Dynamics (UrQMD) approach, combined with an intermediate (3+1)-dimensional ideal hydrodynamical evolution phase using a chiral model equation of state. We find the decrease of v_2 produced by hydrodynamics at lower collision energies partially compensated by the transport dynamics. This does not apply to v_3, which falls to 0 in midcentral collisions at sqrt(s_{NN}) = 5 GeV. We conclude that the triangular flow provides the clearer signal for the formation of low-viscous fluid in heavy ion collisions.
Water Modeling of Steel Flow, Air Entrainment and Filtration
Beckermann, Christoph
Water Modeling of Steel Flow, Air Entrainment and Filtration Christoph Beckermann Associate Beckermann, C., "Water Modeling of Steel Flow, Air Entrainment and Filtration," in Proceedings of the 46th, 1992. #12;Abstract This paper presents an analysis of water modeling of steel pouring to study (1) air
USER�S GUIDE of TOUGH2-EGS-MP: A Massively Parallel Simulator with Coupled Geomechanics for Fluid and Heat Flow in Enhanced Geothermal Systems VERSION 1.0
Xiong, Yi [Colorado School of Mines; Fakcharoenphol, Perapon [Colorado School of Mines; Wang, Shihao [Colorado School of Mines; Winterfeld, Philip H. [Colorado School of Mines; Zhang, Keni [Lawrence Berkeley National Laboratory; Wu, Yu-Shu [Colorado School of Mines
TOUGH2-EGS-MP is a parallel numerical simulation program coupling geomechanics with fluid and heat flow in fractured and porous media, and is applicable for simulation of enhanced geothermal systems (EGS). TOUGH2-EGS-MP is based on the TOUGH2-MP code, the massively parallel version of TOUGH2. In TOUGH2-EGS-MP, the fully-coupled flow-geomechanics model is developed from linear elastic theory for thermo-poro-elastic systems and is formulated in terms of mean normal stress as well as pore pressure and temperature. Reservoir rock properties such as porosity and permeability depend on rock deformation, and the relationships between these two, obtained from poro-elasticity theories and empirical correlations, are incorporated into the simulation. This report provides the user with detailed information on the TOUGH2-EGS-MP mathematical model and instructions for using it for Thermal-Hydrological-Mechanical (THM) simulations. The mathematical model includes the fluid and heat flow equations, geomechanical equation, and discretization of those equations. In addition, the parallel aspects of the code, such as domain partitioning and communication between processors, are also included. Although TOUGH2-EGS-MP has the capability for simulating fluid and heat flows coupled with geomechanical effects, it is up to the user to select the specific coupling process, such as THM or only TH, in a simulation. There are several example problems illustrating applications of this program. These example problems are described in detail and their input data are presented. Their results demonstrate that this program can be used for field-scale geothermal reservoir simulation in porous and fractured media with fluid and heat flow coupled with geomechanical effects.
Flow through porous media : from mixing of fluids to triggering of earthquakes
Jha, Birendra, Ph. D. Massachusetts Institute of Technology. Department of Civil and Environmental Engineering
Enhanced oil recovery by displacing oil with solvents such as carbon dioxide requires development of miscibility between the two fluids to maximize the displacement efficiency. Prevention of inadvertent triggering of ...
Interfacial exchange relations for two-fluid vapor-liquid flow : a simplified regime map approach
Kelly, J. E.
A simplified approach is described for selection of the constitutive relations for the inter-phase exchange terms in the two-fluid code, THERMIT. The approach used distinguishes between pre-CHF and post-CHF conditions. ...
Pulsatile flow of a chemically-reacting non-linear fluid
Bridges, Ronald Craig, II
Many complex biological systems, such as blood and polymeric materials, can be approximated as single constituent homogeneous fluids whose properties can change because of the chemical reactions that take place. For instance, the viscosity...
Airfoil Shape Optimization for Transonic Flows of BetheZel'dovichThompson Fluids
Paris-Sud XI, Université de
of gasdynamics : 1 a @a @ s (1) where is the fluid density, a is the sound speed, and s is the entropy of thermodynamic conditions above the liquid/vapor coexistence curve, such that the fundamental derivative
American Institute of Aeronautics and Astronautics Three-dimensional Plasma and Fluid Flow Structures inside a
Roy, Subrata
by fabrication on the order of micrometers to draw or drain the working fluid in the microfluidic system miniaturization, so that it improves the integration into the microfluidic system. Non-mechanical micropumps
High Flash-point Fluid Flow System Aerosol Flammability Study and Combustion Mechanism Analysis
Huang, Szu-Ying
The existence of flammable aerosols creates fire and explosion hazards in the process industry. Due to the operation condition of high pressure circumstances, heat transfer fluids tend to form aerosols when accidental leaking occurs on pipelines...
Modeling of fluids and waves with analytics and numerics
Liang, Xiangdong, Ph. D. Massachusetts Institute of Technology
Capillary instability (Plateau-Rayleigh instability) has been playing an important role in experimental work such as multimaterial fiber drawing and multilayer particle fabrication. Motivated by complex multi-fluid geometries ...
Model for Fracturing Fluid Flowback and Characterization of Flowback Mechanisms
Song, Bo
A large volume of fracturing fluid that may include slick water and various sorts of additives is injected into shale formations along with proppant to create hydraulic fractures which define a stimulated shale volume a shale gas well will actually...
User's manual for the Sandia Waste-Isolation Flow and Transport model (SWIFT).
Reeves, Mark; Cranwell, Robert M.
This report describes a three-dimensional finite-difference model (SWIFT) which is used to simulate flow and transport processes in geologic media. The model was developed for use by the Nuclear Regulatory Commission in the analysis of deep geologic nuclear waste-disposal facilities. This document, as indicated by the title, is a user's manual and is intended to facilitate the use of the SWIFT simulator. Mathematical equations, submodels, application notes, and a description of the program itself are given herein. In addition, a complete input data guide is given along with several appendices which are helpful in setting up a data-input deck. Computer code SWIFT (Sandia Waste Isolation, Flow and Transport Model) is a fully transient, three-dimensional model which solves the coupled equations for transport in geologic media. The processes considered are: (1) fluid flow; (2) heat transport; (3) dominant-species miscible displacement; and (4) trace-species miscible displacement. The first three processes are coupled via fluid density and viscosity. Together they provide the velocity field on which the fourth process depends.
The effect of various mixers on the viscosity and flow properties of an oil well drilling fluid
Spannagel, Johnny Allen
of Texas in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE January, 1957 MaJor SubJect. Petroleum Englneerlng THE EFFECT OF VARIOUS MIXERS ON THE VISCOSITY AND FLOW PROPERTIES QF AN OIL WELL DRILLING FLUID A Thesis... on the 300 rpm Farm V-G Meter Reading 15 The Effect of Various Mixers on the 600 rpm Farm V-G Meter Reading 15 The Effect of Various Mixers on the Plastic Viscosity of a Bentonite Mud 16 Temperature Variation of the Drilling Mud Mixed in Variou...
Fluid-rock interactions in the Rhine Graben: A thermodynamic model of the hydrothermal alteration observed in deep drilling
Komninou, A.; Yardley, B.W.D. [Univ. of Leeds (United Kingdom)] [Univ. of Leeds (United Kingdom)
Deep drilling at Soultz-sous-Forets, France, on the western flanks of the Rhine Graben, has penetrated Hercynian granite underlying Mesozoic sediments. Veins are present throughout the drilled granite, and there are flows of warm water localized in fractures within the granite. Detailed mineralogical study of core material from the research drillhole EPSI has been carried out in order to assess the alteration history of the Soultz granite, part of the crystalline basement of the Rhine Graben. The results of the study have been used, in conjunction with analyses of present-day fluids from deep drilling in the Rhine Graben reported in the literature, to model thermodynamically the alteration process, and in particular to evaluate if it is likely to be continuing today. Reaction-path calculations show that if deep basinal brines, such as are known from sediments of the central Rhine Graben, react with Hercynian granite, they will form different alteration assemblages depending on both the path that the fluid follows (e.g., descending through sediments or through granite) and the extent of preexisting alteration of the granite. The calculations suggest that fluid now sampled from granite in EPS-1 achieved its peak temperature, c. 200{degrees}C while within Permo-Triassic sandstone. The modeling also indicates that present-day fluids from the Rhine Graben system are capable of producing the vein quartz and possibly also the baryte veins, seen in the EPSI core. Much of the alteration present in the granite in the vicinity of veins and fractures may have been produced by a flow regime similar to that prevailing today. 48 refs., 15 figs., 4 tabs.
Model for the spatio-temporal intermittency of the energy dissipation in turbulent flows
Fabio Lepreti; Vincenzo Carbone; Pierluigi Veltri
Modeling the intermittent behavior of turbulent energy dissipation processes both in space and time is often a relevant problem when dealing with phenomena occurring in high Reynolds number flows, especially in astrophysical and space fluids. In this paper, a dynamical model is proposed to describe the spatio-temporal intermittency of energy dissipation rate in a turbulent system. This is done by using a shell model to simulate the turbulent cascade and introducing some heuristic rules, partly inspired by the well known $p$-model, to construct a spatial structure of the energy dissipation rate. In order to validate the model and to study its spatially intermittency properties, a series of numerical simulations have been performed. These show that the level of spatial intermittency of the system can be simply tuned by varying a single parameter of the model and that scaling laws in agreement with those obtained from experiments on fully turbulent hydrodynamic flows can be recovered. It is finally suggested that the model could represent a useful tool to simulate the spatio-temporal intermittency of turbulent energy dissipation in those high Reynolds number astrophysical fluids where impulsive energy release processes can be associated to the dynamics of the turbulent cascade.
Continuum-kinetic-microscopic model of lung clearance due to core-annular fluid entrainment
Mitran, Sorin, E-mail: email@example.com
The human lung is protected against aspirated infectious and toxic agents by a thin liquid layer lining the interior of the airways. This airway surface liquid is a bilayer composed of a viscoelastic mucus layer supported by a fluid film known as the periciliary liquid. The viscoelastic behavior of the mucus layer is principally due to long-chain polymers known as mucins. The airway surface liquid is cleared from the lung by ciliary transport, surface tension gradients, and airflow shear forces. This work presents a multiscale model of the effect of airflow shear forces, as exerted by tidal breathing and cough, upon clearance. The composition of the mucus layer is complex and variable in time. To avoid the restrictions imposed by adopting a viscoelastic flow model of limited validity, a multiscale computational model is introduced in which the continuum-level properties of the airway surface liquid are determined by microscopic simulation of long-chain polymers. A bridge between microscopic and continuum levels is constructed through a kinetic-level probability density function describing polymer chain configurations. The overall multiscale framework is especially suited to biological problems due to the flexibility afforded in specifying microscopic constituents, and examining the effects of various constituents upon overall mucus transport at the continuum scale.
Modeling and Control of High-Velocity Oxygen-Fuel (HVOF) Thermal Spray: A Tutorial Review
Li, Mingheng; Christofides, Panagiotis D.
Fluid Dynamics Analysis of a Wire- Feed, High-Velocity Oxygen Fuel (Fluid Dynamic Modeling of Gas Flow Charac- teristics in a High-Velocity Oxy-Fuel
A model for P-wave attenuation and dispersion in a porous medium ...
Theoretical models of attenuation and dispersion due to wave-induced fluid flow ...... anisotropic layered fluid- and gas-saturated sediments, Geophysics, 62,.
An improved model for flashing flow in short tubes
Tilton, J.D.; Kornhauser, A.A. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Mechanical Engineering
Short tube restrictors are commonly used as expansion devices in refrigeration and heat pumping systems. Flashing flow through short tubes is choked, i.e. independent of downstream conditions. Flow rate is typically predicted by empirically correcting the flow rate of compressed liquid from upstream pressure to saturation pressure at upstream temperature. The empirical correction factors depend on pressure and temperature, on short tube geometry, and on the refrigerant used. This work extends and improves a model of short tube flow based on the physics of the observed flow phenomena. Short tube flow is believed to consist of a core of superheated liquid surrounded by an annulus of vapor. Evaporation is driven by heat transfer form the core to tine interface, and the flow is choked by the evaporated vapor. Flow rate is modeled by calculating the heat transfer rate, the evaporation rate, and the choking effect of the vapor. The model attempts to improve on previous work by improving the accuracy with which thermodynamic properties are approximated, by improving the heat transfer model, and by including the effects of frictional heating of the liquid. In comparisons with experimental data it is found that the improved thermodynamic modeling increases accuracy, but the change to the heat transfer model reduces accuracy. For the data examined the effects of the frictional heating are small. The heat transfer model is based on an existing analytic solution with a mixing-length turbulence model. It appears that this model must be further improved, perhaps through empirical modification.
ShowFlow: A practical interface for groundwater modeling
Tauxe, J.D.
ShowFlow was created to provide a user-friendly, intuitive environment for researchers and students who use computer modeling software. What traditionally has been a workplace available only to those familiar with command-line based computer systems is now within reach of almost anyone interested in the subject of modeling. In the case of this edition of ShowFlow, the user can easily experiment with simulations using the steady state gaussian plume groundwater pollutant transport model SSGPLUME, though ShowFlow can be rewritten to provide a similar interface for any computer model. Included in this thesis is all the source code for both the ShowFlow application for Microsoft{reg sign} Windows{trademark} and the SSGPLUME model, a User's Guide, and a Developer's Guide for converting ShowFlow to run other model programs. 18 refs., 13 figs.
Nonlinear elasto-plastic model for dense granular flow
Ken Kamrin
This work proposes a model for granular deformation that predicts the stress and velocity profiles in well-developed dense granular flows. Recent models for granular elasticity (Jiang and Liu 2003) and rate-sensitive plastic flow (Jop et al. 2006) are reformulated and combined into one universal granular continuum law, capable of predicting flowing regions and stagnant zones simultaneously in any arbitrary 3D flow geometry. The unification is performed by justifying and implementing a Kroner-Lee elasto-plastic decomposition, with care taken to ensure certain continuum physical principles are necessarily upheld. The model is then numerically implemented in multiple geometries and results are compared to experiments and discrete simulations.
A refined volume-of-fluid algorithm for capturing sharp fluid interfaces on arbitrary meshes
Zhang, Di; Jiang, Chunbo; Liang, Dongfang; Chen, Zhengbing; Yang, Yan; Shi, Ying
conserve mass, and can be easily extended to unstructured meshes and three dimensions, so they are capable of accurately capturing the free surface and modelling merging and fragmentation in multiphase flows. In this article, a new blended high... -tracking method for the computations of multiphase flow. Journal of Computational Physics 2001; 169(2): 708�759. 21 14. Harlow FH, Welch JE. Numerical calculation of time-dependent viscous incompressible flow of fluid with free surface. Physics of Fluids...
Use of Geophysical Techniques to Characterize Fluid Flow in a Geothermal Reservoir
Broader source: Energy.gov [DOE]
Project objectives: Joint inversion of geophysical data for ground water flow imaging; Reduced the cost in geothermal exploration and monitoring; & Combined passive and active geophysical methods.
A correction function method to solve incompressible fluid flows to high accuracy with immersed geometries
Marques, Alexandre Noll
Numerical simulations of incompressible viscous flows in realistic configurations are increasingly important in many scientific and engineering fields. In Aeronautics, for instance, relatively cheap numerical computations ...
Experimental Modeling of VHTR Plenum Flows during Normal Operation and Pressurized Conduction Cooldown
Glenn E McCreery; Keith G Condie
The Very High Temperature Reactor (VHTR) is the leading candidate for the Next Generation Nuclear Power (NGNP) Project in the U.S. which has the goal of demonstrating the production of emissions free electricity and hydrogen by 2015. The present document addresses experimental modeling of flow and thermal mixing phenomena of importance during normal or reduced power operation and during a loss of forced reactor cooling (pressurized conduction cooldown) scenario. The objectives of the experiments are, 1), provide benchmark data for assessment and improvement of codes proposed for NGNP designs and safety studies, and, 2), obtain a better understanding of related phenomena, behavior and needs. Physical models of VHTR vessel upper and lower plenums which use various working fluids to scale phenomena of interest are described. The models may be used to both simulate natural convection conditions during pressurized conduction cooldown and turbulent lower plenum flow during normal or reduced power operation.
NMR imaging techniques and applications in the flow behavior of fluids in porous media
Halimi, Hassan I
proton magnetic resonance technique can be used to determine the oil saturation in the pores of a rock. The NMR system can produce images of the molecules under investigation because the signals recorded are obtained directly from fluids contained... in liquids as well. This should enable us to obtain additional information about the fluids in the rock '4. Spin-spin relaxation has a characteristic time T~. T~ is the time constant for the decay of the precessing R-Zo component of the magnetization...
Integrated Nozzle Flow, Spray, Combustion, & Emission Modeling...
Broader source: Energy.gov (indexed) [DOE]
Technologies Program Office Program Manager: Mr. Gurpreet Singh Petrodiesel vs. Biodiesel 2 Primary Breakup Inner Nozzle Flow Influence of Physical and Chemical properties of...
Using a multiphase flow code to model the coupled effects of repository consolidation and multiphase brine and gas flow at the Waste Isolation Pilot Plant
Freeze, G.A. [INTERA Inc., Albuquerque, NM (United States); Larson, K.W.; Davies, P.B.; Webb, S.W. [Sandia National Labs., Albuquerque, NM (United States)
Long-term repository assessment must consider the processes of (1) gas generation, (2) room closure and expansions due to salt creep, and (3) multiphase (brine and gas) fluid flow, as well as the complex coupling between these three processes. The mechanical creep closure code SANCHO was used to simulate the closure of a single, perfectly sealed disposal room filled with water and backfill. SANCHO uses constitutive models to describe salt creep, waste consolidation, and backfill consolidation, Five different gas-generation rate histories were simulated, differentiated by a rate multiplier, f, which ranged from 0.0 (no gas generation) to 1.0 (expected gas generation under brine-dominated conditions). The results of the SANCHO f-series simulations provide a relationship between gas generation, room closure, and room pressure for a perfectly sealed room. Several methods for coupling this relationship with multiphase fluid flow into and out of a room were examined. Two of the methods are described.
Transient Temperature Modeling For Wellbore Fluid Under Static and Dynamic Conditions
Ali, Muhammad
during the test necessitates that effects of unsteady temperature changes are taken into account for accurate calculation of downhole pressure. The single rate injection model predicts transient temperature of wellbore fluids during injection operations...
A Smoothed Particle Hydrodynamics-Based Fluid Model With a Spatially...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
A Smoothed Particle Hydrodynamics-Based Fluid Model With a Spatially Dependent Viscosity Authors: Martys, N.S., George, W.L., Chun, B., Lootens, D. A smoothed particle...
Numerical and analytical modeling of heat transfer between fluid and fractured rocks
Li, Wei, S.M. Massachusetts Institute of Technology
Modeling of heat transfer between fluid and fractured rocks is of particular importance for energy extraction analysis in EGS, and therefore represents a critical component of EGS design and performance evaluation. In ...
Analysis of fluid flow and heat transfer in a rib grit roughened surface solar air heater using CFD
Karmare, S.V. [Department of Mechanical Engineering, Government College Engineering, Karad 415 124, Maharashtra (India); Shivaji University, Kolhapur, Maharashtra (India); Tikekar, A.N. [Department of Mechanical Engineering, Walchand College of Engineering, Sangli (India); Shivaji University, Kolhapur, Maharashtra (India)
This paper presents the study of fluid flow and heat transfer in a solar air heater by using Computational Fluid Dynamics (CFD) which reduces time and cost. Lower side of collector plate is made rough with metal ribs of circular, square and triangular cross-section, having 60 inclinations to the air flow. The grit rib elements are fixed on the surface in staggered manner to form defined grid. The system and operating parameters studied are: e/D{sub h} = 0.044, p/e = 17.5 and l/s = 1.72, for the Reynolds number range 3600-17,000. To validate CFD results, experimental investigations were carried out in the laboratory. It is found that experimental and CFD analysis results give the good agreement. The optimization of rib geometry and its angle of attack is also done. The square cross-section ribs with 58 angle of attack give maximum heat transfer. The percentage enhancement in the heat transfer for square plate over smooth surface is 30%. (author)
A new, efficient computational model for the prediction of fluid seal flowfields
Hibbs, Robert Irwin
A NEW) EFFICIENT COMPUTATIONAL MODEL FOR THE PREDICTION OF FLUID SEAL FLOWFIELDS A Thesis by ROBERT IRWIN HIBBS, JR. Submitted to the Office of Graduate Studies of Texas ASM University in partial fulfillment of the requirement for the degree... of MASTER OF SCIENCE December 1988 Major Subject: Mechanical Engineering A NEW, EFFICIENT COMPUTATIONAL MODEL FOR THE PREDICTION OF FLUID SEAL FLOWFIELDS A Thesis by ROBERT IRWIN HIBBS, JR. Approved as to style and content by: David L. Rhode...
Moses Bogere
The overall objective of the project was to verify the applicability of the FCMOM approach to the kinetic equations describing the particle flow dynamics. For monodispersed systems the fundamental equation governing the particle flow dynamics is the Boltzmann equation. During the project, the FCMOM was successfully applied to several homogeneous and in-homogeneous problems in different flow regimes, demonstrating that the FCMOM has the potential to be used to solve efficiently the Boltzmann equation. However, some relevant issues still need to be resolved, i.e. the homogeneous cooling problem (inelastic particles cases) and the transition between different regimes. In this report, the results obtained in homogeneous conditions are discussed first. Then a discussion of the validation results for in-homogeneous conditions is provided. And finally, a discussion will be provided about the transition between different regimes. Alongside the work on development of FCMOM approach studies were undertaken in order to provide insights into anisotropy or particles kinetics in riser hydrodynamics. This report includes results of studies of multiphase flow with unequal granular temperatures and analysis of momentum re-distribution in risers due to particle-particle and fluid-particle interactions. The study of multiphase flow with unequal granular temperatures entailed both simulation and experimental studies of two particles sizes in a riser and, a brief discussion of what was accomplished will be provided. And finally, a discussion of the analysis done on momentum re-distribution of gas-particles flow in risers will be provided. In particular a discussion of the remaining work needed in order to improve accuracy and predictability of riser hydrodynamics based on two-fluid models and how they can be used to model segregation in risers.
LETTER TO THE EDITOR AC Electric-Field-Induced Fluid Flow in Microelectrodes
glass substrates. The electrodes were made from a series of metal layers: 10 nm Ti, 10 nm Pd, 100 nm Au relaxation time, with a reproducible pattern occurring close to and across the electrode surface. This paper reports measurements of the fluid velocity as a function of frequency and position across the electrode
A Well-Balanced Scheme For Two-Fluid Flows In Variable Cross-Section ducts
Paris-Sud XI, Université de
, ) p = p(, s, ), h = h(, s, ). (21) Then in these variables the sound speed c satisfies c2 = p = h. (22 of a mixture of two compressible fluids (a gas (1) and a liquid (2), for instance) in a cross-section duct
Solyndra Facts vs. Fiction: Cash Flow Modeling
Broader source: Energy.gov [DOE]
Questions have been raised about a quote selectively pulled from an Aug. 20, 2009 email to make it look like Solyndra would run out of cash by Sept. 2011. To be clear, the analysis addressed in that email did not refer to Solyndra�s corporate cash flow, but rather the cash flow for a subsidiary of Solyndra � the �Fab 2 Project Company.
Modeling Granular Materials as Compressible Non-Linear Fluids: Heat Transfer Boundary Value Problems
Massoudi, M.C.; Tran, P.X.
We discuss three boundary value problems in the flow and heat transfer analysis in flowing granular materials: (i) the flow down an inclined plane with radiation effects at the free surface; (ii) the natural convection flow between two heated vertical walls; (iii) the shearing motion between two horizontal flat plates with heat conduction. It is assumed that the material behaves like a continuum, similar to a compressible nonlinear fluid where the effects of density gradients are incorporated in the stress tensor. For a fully developed flow the equations are simplified to a system of three nonlinear ordinary differential equations. The equations are made dimensionless and a parametric study is performed where the effects of various dimensionless numbers representing the effects of heat conduction, viscous dissipation, radiation, and so forth are presented.
A two-fluid model for relativistic heat conduction
L�pez-Monsalvo, C�sar S. [Instituto de Ciencias Nucleares, Universidad Nacional Aut�noma de M�xico (Mexico)
Three years ago it was presented in these proceedings the relativistic dynamics of a multi-fluid system together with various applications to a set of topical problems [1]. In this talk, I will start from such dynamics and present a covariant formulation of relativistic thermodynamics which provides us with a causal constitutive equation for the propagation of heat in a relativistic setting.
Two fluid anisotropic dark energy models in a scale invariant theory
Tripathy, S K; Sahoo, P K
We have investigated some anisotropic dark energy models in a simple scale invariant theory of gravity. The anisotropic nature of the universe is considered through a spatially homogeneous and anisotropic Bianchi type $V$ space-time. The matter field is considered to be composed of two non interacting fluids namely the usual bulk viscous fluid and that of the dark energy fluid. Pressure anisotropy is considered along different spatial directions. From the constructed cosmological models, we found a dynamic pressure anisotropy which continues along with the cosmic expansion. The models are found to be mostly dominated by phantom behaviour. The presence of bulk viscous fluid does not affect substantially the general nature of the cosmic dynamics. The scale invariant theory of gravity is found to have a dominant role in the cosmic dynamics and help the de Sitter universe to exit from a catastrophic situation.
Integration of an Aggregate Flow Model with a Traffic Flow Simulator
Integration of an Aggregate Flow Model with a Traffic Flow Simulator Robert Hoffman , Dengfeng Sun restrictions to aircraft movement are applied by air traffic controllers and traffic managers in response to demand overages or capacity shortfalls in sectors of airspace. To estimate and assess the efficiency
Data-flow graphs as a model of parallel complexity
Campbell, M.L.
A new model of parallel computation based on data-flow graphs is introduced, which is specifically oriented towards complexity theory. Data-flow graphs are capable of illustrating properties of synchronous, asynchronous, and nondeterministic computations. Sufficient conditions are derived for asynchronous data-flow graphs to be determinate, i.e., all possible computations are finite and yield the same result. For determinate graphs, it is shown that the synchronous computation is as fast as any asynchronous computation. An algorithm is presented that transforms a nondeterminate data-flow graphs into a synchronous determinate one. The basic data-flow graph idea is extended into a model with greater potential parallelism, called the Uniform Data Flow Graph Family (UDFGF) Model. It is proved that time and space for the UDFGF model are polynomially related to reversal and space for the Turing Machine model, in both the deterministic and nondeterministic cases. In addition to forming an abstract computational model, data-flow graphs are parallel programs for real multiprocessors. Given a data flow graph program and a multiprocessor, each node of the graph must be assigned to one of the processors. It is proved that this problem is intractable, and a practical algorithm to find approximate solutions for it is presented.
Measurement of Flow Phenomena in a Lower Plenum Model of a Prismatic Gas-Cooled Reactor
Hugh M. McIlroy, Jr.; Doanld M. McEligot; Robert J. Pink
Mean-velocity-field and turbulence data are presented that measure turbulent flow phenomena in an approximately 1:7 scale model of a region of the lower plenum of a typical prismatic gas-cooled reactor (GCR) similar to a General Atomics Gas-Turbine-Modular Helium Reactor (GTMHR) design. The data were obtained in the Matched-Index-of-Refraction (MIR) facility at Idaho National Laboratory (INL) and are offered for assessing computational fluid dynamics (CFD) software. This experiment has been selected as the first Standard Problem endorsed by the Generation IV International Forum. Results concentrate on the region of the lower plenum near its far reflector wall (away from the outlet duct). The flow in the lower plenum consists of multiple jets injected into a confined cross flow - with obstructions. The model consists of a row of full circular posts along its centerline with half-posts on the two parallel walls to approximate geometry scaled to that expected from the staggered parallel rows of posts in the reactor design. The model is fabricated from clear, fused quartz to match the refractive-index of the working fluid so that optical techniques may be employed for the measurements. The benefit of the MIR technique is that it permits optical measurements to determine flow characteristics in complex passages in and around objects to be obtained without locating intrusive transducers that will disturb the flow field and without distortion of the optical paths. An advantage of the INL system is its large size, leading to improved spatial and temporal resolution compared to similar facilities at smaller scales. A three-dimensional (3-D) Particle Image Velocimetry (PIV) system was used to collect the data. Inlet jet Reynolds numbers (based on the jet diameter and the time-mean bulk velocity) are approximately 4,300 and 12,400. Uncertainty analyses and a discussion of the standard problem are included. The measurements reveal developing, non-uniform, turbulent flow in the inlet jets and complicated flow patterns in the model lower plenum. Data include three-dimensional vector plots, data displays along the coordinate planes (slices) and presentations that describe the component flows at specific regions in the model. Information on inlet conditions is also presented.
A Novel Approach For the Simulation of Multiple Flow Mechanisms and Porosities in Shale Gas Reservoirs
Yan, Bicheng
The state of the art of modeling fluid flow in shale gas reservoirs is dominated by dual porosity models that divide the reservoirs into matrix blocks that significantly contribute to fluid storage and fracture networks which principally control...
Formulation, Implementation and Validation of a Two-Fluid model in a Fuel Cell CFD Code
Kunal Jain, Vernon Cole, Sanjiv Kumar and N. Vaidya
Water management is one of the main challenges in PEM Fuel Cells. While water is essential for membrane electrical conductivity, excess liquid water leads to ooding of catalyst layers. Despite the fact that accurate prediction of two-phase transport is key for optimal water management, understanding of the two-phase transport in fuel cells is relatively poor. Wang et. al. [1], [2] have studied the two-phase transport in the channel and diffusion layer separately using a multiphase mixture model. The model fails to accurately predict saturation values for high humidity inlet streams. Nguyen et. al. [3] developed a two-dimensional, two-phase, isothermal, isobaric, steady state model of the catalyst and gas diffusion layers. The model neglects any liquid in the channel. Djilali et. al. [4] developed a three-dimensional two-phase multicomponent model. The model is an improvement over previous models, but neglects drag between the liquid and the gas phases in the channel. In this work, we present a comprehensive two- fluid model relevant to fuel cells. Models for two-phase transport through Channel, Gas Diffusion Layer (GDL) and Channel-GDL interface, are discussed. In the channel, the gas and liquid pressures are assumed to be same. The surface tension effects in the channel are incorporated using the continuum surface force (CSF) model. The force at the surface is expressed as a volumetric body force and added as a source to the momentum equation. In the GDL, the gas and liquid are assumed to be at different pressures. The difference in the pressures (capillary pressure) is calculated using an empirical correlations. At the Channel-GDL interface, the wall adhesion affects need to be taken into account. SIMPLE-type methods recast the continuity equation into a pressure-correction equation, the solution of which then provides corrections for velocities and pressures. However, in the two-fluid model, the presence of two phasic continuity equations gives more freedom and more complications. A general approach would be to form a mixture continuity equation by linearly combining the phasic continuity equations using appropriate weighting factors. Analogous to mixture equation for pressure correction, a difference equation is used for the volume/phase fraction by taking the difference between the phasic continuity equations. The relative advantages of the above mentioned algorithmic variants for computing pressure correction and volume fractions are discussed and quantitatively assessed. Preliminary model validation is done for each component of the fuel cell. The two-phase transport in the channel is validated using empirical correlations. Transport in the GDL is validated against results obtained from LBM and VOF simulation techniques. The Channel-GDL interface transport will be validated against experiment and empirical correlation of droplet detachment at the interface. References [1] Y. Wang S. Basu and C.Y. Wang. Modeling two-phase flow in pem fuel cell channels. J. Power Sources, 179:603{617, 2008. [2] P. K. Sinha and C. Y. Wang. Liquid water transport in a mixed-wet gas diffusion layer of a polymer electrolyte fuel cell. Chem. Eng. Sci., 63:1081-1091, 2008. [3] Guangyu Lin and Trung Van Nguyen. A two-dimensional two-phase model of a pem fuel cell. J. Electrochem. Soc., 153(2):A372{A382, 2006. [4] T. Berning and N. Djilali. A 3d, multiphase, multicomponent model of the cathode and anode of a pem fuel cell. J. Electrochem. Soc., 150(12):A1589{A1598, 2003.
Fusion Engineering and Design 82 (2007) 22172225 Integrated thermo-fluid analysis towards helium flow
Abdou, Mohamed
flow path design for an ITER solid breeder blanket module A. Yinga,, M. Narulaa, R. Hunta, M. Abdoua, Y breeder blanket design. Supplying all s the ITER test blanket module (TBM) warrants the need of extensive computer aided engineering (CAE
Fluid Flow In The Resurgent Dome Of Long Valley Caldera- Implications...
caldera was cooled to normal thermal conditions by vigorous hydrothermal activity in the past, and that a present-day hot water flow system is responsible for local hot anomalies,...
Review of fluid flow and convective heat transfer within rotating disk cavities
Boyer, Edmond
-00975626,version1-8Apr2014 Author manuscript, published in "International Journal of Thermal Sciences 67 based on and r. Rej Jet Reynolds number based on W and D. ReU Cross-flow Reynolds number Ro Rossby
On the Fundamental Unsteady Fluid Dynamics of Shock-Induced Flows through Ducts
Mendoza, Nicole Renee
Unsteady shock wave propagation through ducts has many applications, ranging from blast wave shelter design to advanced high-speed propulsion systems. The research objective of this study was improved fundamental understanding of the transient flow...
Molecular modelling and simulation of the surface tension of real quadrupolar fluids
Stephan Werth; Katrin St�bener; Peter Klein; Karl-Heinz K�fer; Martin Horsch; Hans Hasse
Molecular modelling and simulation of the surface tension of fluids with force fields is discussed. 29 real fluids are studied, including nitrogen, oxygen, carbon dioxide, carbon monoxide, fluorine, chlorine, bromine, iodine, ethane, ethylene, acetylene, propyne, propylene, propadiene, carbon disulfide, sulfur hexafluoride, and many refrigerants. The fluids are represented by two-centre Lennard-Jones plus point quadrupole models from the literature. These models were adjusted only to experimental data of the vapour pressure and saturated liquid density so that the results for the surface tension are predictions. The deviations between the predictions and experimental data for the surface tension are of the order of 20 percent. The surface tension is usually overestimated by the models. For further improvements, data on the surface tension can be included in the model development. A suitable strategy for this is multi-criteria optimization based on Pareto sets. This is demonstrated using the model for carbon dioxide as an example.
A Novel Hyperbolization Procedure for The Two-Phase Six-Equation Flow Model
Samet Y. Kadioglu; Robert Nourgaliev; Nam Dinh
We introduce a novel approach for the hyperbolization of the well-known two-phase six equation flow model. The six-equation model has been frequently used in many two-phase flow applications such as bubbly fluid flows in nuclear reactors. One major drawback of this model is that it can be arbitrarily non-hyperbolic resulting in difficulties such as numerical instability issues. Non-hyperbolic behavior can be associated with complex eigenvalues that correspond to characteristic matrix of the system. Complex eigenvalues are often due to certain flow parameter choices such as the definition of inter-facial pressure terms. In our method, we prevent the characteristic matrix receiving complex eigenvalues by fine tuning the inter-facial pressure terms with an iterative procedure. In this way, the characteristic matrix possesses all real eigenvalues meaning that the characteristic wave speeds are all real therefore the overall two-phase flowmodel becomes hyperbolic. The main advantage of this is that one can apply less diffusive highly accurate high resolution numerical schemes that often rely on explicit calculations of real eigenvalues. We note that existing non-hyperbolic models are discretized mainly based on low order highly dissipative numerical techniques in order to avoid stability issues.
Modelling general relativistic perfect fluids in field theoretic language
Nikolai V. Mitskievich
Skew-symmetric massless fields, their potentials being $r$-forms, are close analogues of Maxwell's field (though the non-linear cases also should be considered). We observe that only two of them ($r=$2 and 3) automatically yield stress-energy tensors characteristic to normal perfect fluids. It is shown that they naturally describe both non-rotating ($r=2$) and rotating (then a combination of $r=2$ and $r=3$ fields is indispensable) general relativistic perfect fluids possessing every type of equations of state. Meanwile, a free $r=3$ field is completely equivalent to appearance of the cosmological term in Einstein's equations. Sound waves represent perturbations propagating on the background of the $r=2$ field. Some exotic properties of these two fields are outlined.
Mathematical Model Analysis for Hg Flow
McDonald, Kirk
Properties (25 C ) Density 13.546 kg/L Sound Speed 1451 m/s Viscosity 1.526E-3 kg/sm Dynamic Viscosity 1Mechanism of Jet Breakup & Atomization R.D. Reitz and F.V. Bracco, Mechanism of atomization of a liquid jet,Phys. Fluids, Vol.25, No.10,Oct.1982 Environment Liquid Properties Viscosity Density Jet Breakup & Atomization
Model Predictive Control of Variable Density Multiphase Flows Governed by
Hinze, Michael
of model predictive control (MPC) consists in steering or keeping the state of a dynamical systemModel Predictive Control of Variable Density Multiphase Flows Governed by Diffuse Interface Models appearing in the model predictive control strategy. The resulting control concept is known as instantaneous
Modeling of material and energy flow in an EBCHR casting system
Westerberg, K.W. [Aspen Technology, Inc., Cambridge, MA (United States); McClelland, M.A. [Lawrence Livermore National Lab., CA (United States)
A numerical and experimental analysis is made of fluid flow and heat transfer in a continuous casting system with an electron-beam energy source. For a cylindrical ingot confined in a water-cooled crucible, a two-dimensional, steady-state model is developed which includes the effects of free convection in the pool and conduction in the two-phase and solid regions. A modified Galerkin finite element method is used to solve for the flow and temperature fields simultaneously with the upper and lower boundaries of the pool. The calculation grid deforms along vertical spines as these phase boundaries move. Heat flows are measured in a steady-state experiment involving a short ingot and no pouring. Heat transfer coefficients representing contact resistance are determined, and measured heat flows are compared with model values. Flow and temperature fields along with solidification-zone boundaries are calculated for the experimental case and a case in which the ingot cooling is improved.
Modeling of material and energy flow in an EBCHR casting system
Westerberg, K.W. [Aspen Technology, Inc., Cambridge, MA (United States); McClelland, M.A. [Lawrence Livermore National Lab., CA (United States)
A numerical and experimental analysis is made of fluid flow and heat transfer in a continuous casting system with an electron-beam energy source. For a cylindrical ingot confined in a water-cooled crucible, a two-dimensional, steady-state model is developed which includes the effects of free convection in the pool and conduction in the two-phase and solid regions. A modified Galerkin finite element method is used to solve for the flow and temperature fields simultaneously with the upper and lower boundaries of the pool. The calculation grid deforms along vertical spines as these phase boundaries move. Heat flows are measured in a steady-state experiment involving a short ingot and no pouring. Heat transfer coefficients representing contact resistance are determined, and measured heat flows are compared with model values. Flow and temperature fields along with solidification-zone boundaries are calculated for the experimental case and a case in which the ingot cooling is improved.
Three-dimensional computer modeling of particulate flow around dust monitors
Nichols, B.D.; Gregory, W.S.
SOLA-DM is a three-dimensional finite-difference computer code designed to model the dynamics of an incompressible fluid and the transport of discrete particulate material around obstacles impervious to flow. The numerical methods used in this code are described. SOLA-DM was used to predict the particle flux sampled by the 10-mm Dorr-Oliver Cyclone and MINIRAM dust monitors. Various geometric and dynamic variations of monitor and airflow combinations were tested. The code predictions are shown in computer-generated graphic plots.
A General Nonlinear Fluid Model for Reacting Plasma-Neutral Mixtures
Meier, E T; Shumlak, U
A generalized, computationally tractable fluid model for capturing the effects of neutral particles in plasmas is derived. The model derivation begins with Boltzmann equations for singly charged ions, electrons, and a single neutral species. Electron-impact ionization, radiative recombination, and resonant charge exchange reactions are included. Moments of the reaction collision terms are detailed. Moments of the Boltzmann equations for electron, ion, and neutral species are combined to yield a two-component plasma-neutral fluid model. Separate density, momentum, and energy equations, each including reaction transfer terms, are produced for the plasma and neutral equations. The required closures for the plasma-neutral model are discussed.
Generating expansion model incorporating compact DC power flow equations
Nderitu, D.G.; Sparrow, F.T.; Yu, Z. [Purdue Inst. for Interdisciplinary Engineering Studies, West Lafayette, IN (United States)
This paper presents a compact method of incorporating the spatial dimension into the generation expansion problem. Compact DC power flow equations are used to provide real-power flow coordination equations. Using these equations the marginal contribution of a generator to th total system loss is formulated as a function of that generator`s output. Incorporating these flow equations directly into the MIP formulation of the generator expansion problem results in a model that captures a generator`s true net marginal cost, one that includes both the cost of generation and the cost of transport. This method contrasts with other methods that iterate between a generator expansion model and an optimal power flow model. The proposed model is very compact and has very good convergence performance. A case study with data from Kenya is used to provide a practical application to the model.
The primary purpose of the tank mixing and sampling demonstration program is to mitigate the technical risks associated with the ability of the Hanford tank farm delivery and celtification systems to measure and deliver a uniformly mixed high-level waste (HLW) feed to the Waste Treatment and Immobilization Plant (WTP) Uniform feed to the WTP is a requirement of 24590-WTP-ICD-MG-01-019, ICD-19 - Interface Control Document for Waste Feed, although the exact definition of uniform is evolving in this context. Computational Fluid Dynamics (CFD) modeling has been used to assist in evaluating scaleup issues, study operational parameters, and predict mixing performance at full-scale.
Modeling and Algorithmic Approaches to Constitutively-Complex, Micro-structured Fluids
Forest, Mark Gregory [University of North Carolina at Chapel Hill] [University of North Carolina at Chapel Hill
The team for this Project made significant progress on modeling and algorithmic approaches to hydrodynamics of fluids with complex microstructure. Our advances are broken down into modeling and algorithmic approaches. In experiments a driven magnetic bead in a complex fluid accelerates out of the Stokes regime and settles into another apparent linear response regime. The modeling explains the take-off as a deformation of entanglements, and the longtime behavior is a nonlinear, far-from-equilibrium property. Furthermore, the model has predictive value, as we can tune microstructural properties relative to the magnetic force applied to the bead to exhibit all possible behaviors. Wave-theoretic probes of complex fluids have been extended in two significant directions, to small volumes and the nonlinear regime. Heterogeneous stress and strain features that lie beyond experimental capability were studied. It was shown that nonlinear penetration of boundary stress in confined viscoelastic fluids is not monotone, indicating the possibility of interlacing layers of linear and nonlinear behavior, and thus layers of variable viscosity. Models, algorithms, and codes were developed and simulations performed leading to phase diagrams of nanorod dispersion hydrodynamics in parallel shear cells and confined cavities representative of film and membrane processing conditions. Hydrodynamic codes for polymeric fluids are extended to include coupling between microscopic and macroscopic models, and to the strongly nonlinear regime.
Perturbative analysis of sheared flow Kelvin-Helmholtz instability in a weakly relativistic magnetized electron fluid
Sundar, Sita; Das, Amita; Kaw, Predhiman [Institute for Plasma Research, Bhat, Gandhinagar-382428 (India)
In the interaction of intense lasers with matter/plasma, energetic electrons having relativistic energies get created. These energetic electrons can often have sheared flow profiles as they propagate through the plasma medium. In an earlier study [Phys. Plasmas 17, 022101 (2010)], it was shown that a relativistic sheared electron flow modifies the growth rate and threshold condition of the conventional Kelvin-Helmholtz instability. A perturbative analytic treatment for the case of weakly relativistic regime has been provided here. It provides good agreement with the numerical results obtained earlier.
On the terminal velocity of sedimenting particles in a flowing fluid
Marco Martins Afonso
The influence of an underlying carrier flow on the terminal velocity of sedimenting particles is investigated both analytically and numerically. Our theoretical framework works for a general class of (laminar or turbulent) velocity fields and, by means of an ordinary perturbation expansion at small Stokes number, leads to closed partial differential equations (PDE) whose solutions contain all relevant information on the sedimentation process. The set of PDE's are solved by means of direct numerical simulations for a class of 2D cellular flows (static and time dependent) and the resulting phenomenology is analysed and discussed.
Confined flow of suspensions modeled by a frictional rheology
Brice Lecampion; Dmitry I. Garagash
We investigate in detail the problem of confined pressure-driven laminar flow of neutrally buoyant non-Brownian suspensions using a frictional rheology based on the recent proposal of Boyer et al., 2011. The friction coefficient and solid volume fraction are taken as functions of the dimensionless viscous number I defined as the ratio between the fluid shear stress and the particle normal stress. We clarify the contributions of the contact and hydrodynamic interactions on the evolution of the friction coefficient between the dilute and dense regimes reducing the phenomenological constitutive description to three physical parameters. We also propose an extension of this constitutive law from the flowing regime to the fully jammed state. We obtain an analytical solution of the fully-developed flow in channel and pipe for the frictional suspension rheology. The result can be transposed to dry granular flow upon appropriate redefinition of the dimensionless number I. The predictions are in excellent agreement with available experimental results, when using the values of the constitutive parameters obtained independently from stress-controlled rheological measurements. In particular, the frictional rheology correctly predicts the transition from Poiseuille to plug flow and the associated particles migration with the increase of the entrance solid volume fraction. We numerically solve for the axial development of the flow from the inlet of the channel/pipe toward the fully-developed state. The available experimental data are in good agreement with our predictions. The solution of the axial development of the flow provides a quantitative estimation of the entrance length effect in pipe for suspensions. A analytical expression for development length is shown to encapsulate the numerical solution in the entire range of flow conditions from dilute to dense.
On preparation of viscous pore fluids for dynamic centrifuge modelling
Adamidis, O.; Madabhushi, S. P. G.
dynamic cen- trifuge tests, the use of water as pore fluid can limit the generation of excess pore pressures in sand formations below gravel embankments, lowering the recorded crest settlement signif- icantly. Chian and Madabhushi [2010] exam- ined... with changing 4 1.2 1.6 2 2.4 2.8 3.2 0 40 80 120 160 200 Concentration [%] V is co si ty [m P a � s] measurements at 20?C best fit (8th order) best fit (power law) Stewart et al. [1998] Figure 2: Viscosity change with concentration 1.2 1.6 2 2.4 2.8 3.2 1...
Numerical simulation of flow of shear-thinning fluids in corrugated channels
Aiyalur Shankaran, Rohit
is subjected to a periodic increase and decrease in cross-section area. Such conditions are frequently observed in the flow of blood through blood vessels, movement of lubricating oils through the ground during the oil extraction process, in the process...
Numerical simulation of flow of shear-thinning fluids in corrugated channels
Aiyalur Shankaran, Rohit
is subjected to a periodic increase and decrease in cross-section area. Such conditions are frequently observed in the flow of blood through blood vessels, movement of lubricating oils through the ground during the oil extraction process, in the process...
Multiphase flow and Encapsulation simulations using the moment of fluid method 1
Sussman, Mark
in order to demonstrate its capabilities. Examples are given in 2D, 3D axisymmetric (R-Z), and 3D (X Corporation, for the U. S. Department of Energy's National Nuclear Security Administration under contract DE. Introduction Multiphase flow plays an important role in many technical applications including ink-jet printing
Slip Flow Fluid-Structure-Interaction J. van Rij, T. Harman, T. Ameel*
Utah, University of
per unit mass E Young's modulus of elasticity, ( )KGGK 39 + f force per unit volume FD drag force Fo Fourier number, 2 Dt G shear modulus of elasticity * Corresponding author. Tel.: +1-801-585-9730; fax: +1 moment of inertia K bulk modulus of elasticity rsK momentum exchange coefficient slip rsK slip flow
Tracer Fluid Flow through Porous Media: Theory Applied to Acid Stimulation Treatments in Carbonate Rocks
Zakaria Mohamed Reda, Ahmed
the flow behavior in vuggy rocks, including the more pronounced works of Hidajat et al. (2004), Moctezuma Berthier et al. (2000), Xu et al. (1998), Zhang et al. (2004 and 2005), and Arbogast et al. (2004). Zhang et al. (2005) conducted number...
Under consideration for publication in J. Fluid Mech. 1 Hydrodynamic effects in channel flow due to
Sen, Mihir
is that of a boundary layer exposed to wall vi- brations. The concept of complia the resulting linear system of equations. Resonance is found in the oscillatory flow at a Strohaul num- ber be applied. 1. Introduction Unsteady boundaries commonly occur in many engineering as well as natural applica
Two-fluid flowing equilibria of compact plasmas Loren C. Steinhauer
Washington at Seattle, University of
or presence of a j�?B force. The force-free class may have significant flows. Spheromaks are in this class-force-free class is energetically favorable. This sheds light on the FRC-spheromak bifurcation observed- perimentally only in certain arrangements reversed-field pinch, spheromak and then only in the central ``core
Imaging Fluid Flow in Geothermal Wells Using Distributed Thermal Perturbation Sensing
Broader source: Energy.gov [DOE]
Project objective: A New Geothermal Well Imaging Tool. 1.To develop a robust and easily deployable DTPS for monitoring in geothermal wells; and 2. Develop the associated analysis methodology for flow imaging; and?when possible by wellbore conditions?to determine in situthermal conductivity and basal heat flux.
Modeling and design of semi-solid flow batteries
Brunini, Victor Eric
A three-dimensional dynamic model of the recently introduced semi-solid flow battery system is developed and applied to address issues with important design and operation implications. Because of the high viscosity of ...
Submarine landslide flows simulation through centrifuge modelling
Gue, Chang Shin
......... 140 � 4.6.4 � Series 4: Experiments at various g le vels with a large flow rate in the dry condition ........................................................................................ 148 � 4.7 � Repeatability of the Centrifuge Experiments... .......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .188 � 5.5.4 � Side wall friction ..................................................................................189 � 5.5.5 � Basal friction and pore pressure ratio ( ? ) ............................................ 194 � 5.6 � Summary...
Modelling macroeconomic flows related to large ensembles
Schellekens, Michel P.
, including, say, oil prices, interest rates, etc; dynamics of shares markets are governed by information)economics is in understanding quantitative relationships which govern flows of money, various commodities, goods and labours or filled by a water, and there is 3 #12;a price, measured in the universal physics currency, energy
Fluid transport in branched structures with temporary closures: A model for quasistatic lung inflation
Alencar, Adriano Mesquita
Fluid transport in branched structures with temporary closures: A model for quasistatic lung a model system relevant to the inflation of a mammalian lung, an asymmetric bifurcating structure description of the underlying branching structure of the lung, by analyzing experimental pressure-volume data
Stability and Asymptotic Analysis of a Fluid-Particle Interaction Model
Goudon, Thierry
-particle interaction is of primarily importance in sedimentation analysis of disperse suspen- sions of particlesStability and Asymptotic Analysis of a Fluid-Particle Interaction Model Jos�e A. Carrillo1-mail: email@example.com Abstract We are interested in coupled microscopic/macroscopic models
A next-generation modeling capability assesses wind turbine array fluid dynamics and aeroelastic simulations
A next-generation modeling capability assesses wind turbine array fluid dynamics and aeroelastic simulations Characterizing and optimizing overall performance of wind plants composed of large numbers at the National Renewable Energy Laboratory (NREL) are coupling physical models of the atmosphere and wind
Thermal Expansion Models of Viscous Fluids Based on Limits of Free Energy
Aluffi, Paolo
Thermal Expansion Models of Viscous Fluids Based on Limits of Free Energy S.E. Bechtel Department March 25, 2002 Abstract Many viscous uid ows are mechanically incompressible, yet thermally expand associated with sound waves. The Boussi- nesq model for laboratory-scale, buoyancy-driven thermal convection
Fluid dynamics of rivulet flow between plates W. Drenckhan, H. Ritacco, A. Saint-Jalmes, A. Saugey, P. McGuinness, A. van der Net, D. Langevin, and D.
Paris-Sud XI, Université de
spaced, vertical glass plates. Such a "rivulet" is bounded by two liquid/solid and two mobile liquid/gas interfaces, posing fluid dynamic problems of direct relevance to local fluid flow in liquid foams/liquid or liquid/gas interfaces, as found in foams and emulsions, which respond to flow by adjusting their shape
Simulations for Complex Fluid Flow Problems from Berkeley Lab's Center for Computational Sciences and Engineering (CCSE)
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
The Center for Computational Sciences and Engineering (CCSE) develops and applies advanced computational methodologies to solve large-scale scientific and engineering problems arising in the Department of Energy (DOE) mission areas involving energy, environmental, and industrial technology. The primary focus is in the application of structured-grid finite difference methods on adaptive grid hierarchies for compressible, incompressible, and low Mach number flows. The diverse range of scientific applications that drive the research typically involve a large range of spatial and temporal scales (e.g. turbulent reacting flows) and require the use of extremely large computing hardware, such as the 153,000-core computer, Hopper, at NERSC. The CCSE approach to these problems centers on the development and application of advanced algorithms that exploit known separations in scale; for many of the application areas this results in algorithms are several orders of magnitude more efficient than traditional simulation approaches.
Proceedings: Joint DOE/NSF Workshop on flow of particulates and fluids
Not Available
These proceedings are the result of the Fifth DOR-NSF Workshop on fundamental research in the area of particulate two-phase flow and granular flow. The present collection of twenty contributions from universities and national laboratories is based on research projects sponsored by either the Department of Energy or the National Science Foundation. These papers illustrate some of the latest advances in theory, simulations, and experiments. The papers from the Workshop held September 29--October 1, 1993 have been separated into three basic areas: experiments, theory, and numerical simulations. A list of attendees at the workshop is included at the end of the proceedings. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.
Materials Science and Engineering B 117 (2005) 5361 Finite element analysis-based design of a fluid-flow control nano-valve
Grujicic, Mica
Materials Science and Engineering B 117 (2005) 53�61 Finite element analysis-based design A finite element method-based procedure is developed for the design of molecularly functionalized nano of a fluid-flow control nano-valve. The results obtained suggest that the finite element-based procedure
Closure models for turbulent reacting flows
Dutta, A.; Tarbell, J.M. (Pennsylvania State Univ., University Park, PA (USA). Dept. of Chemical Engineering)
In this paper, a simple procedure based on fast and slow reaction asymptotics has been employed to drive first-order closure models for the nonlinear reaction terms in turbulent mass balances from mechanistic models of turbulent mixing and reaction. The coalescence-redispersion (CRD) model, the interaction by exchange with the mean (IEM) model, the three-environment (3E) model, and the four-environment (4E) model have been used to develop closure equations. The closure models have been tested extensively against experimental data for both single and multiple reactions. The closures based on slow asymptotics for the CRD, 3E and 4E models provide very good predictions of all of the experimental data, while other models available either in the literature or derived here are not adequate. The simple new closure equations developed in this paper may be useful in modeling systems involving turbulent mixing and complex chemical reactions.
Isomorphic classical molecular dynamics model for an excess electronin a supercritical fluid
Miller III, Thomas F.
Ring polymer molecular dynamics (RPMD) is used to directly simulate the dynamics of an excess electron in a supercritical fluid over a broad range of densities. The accuracy of the RPMD model is tested against numerically exact path integral statistics through the use of analytical continuation techniques. At low fluid densities, the RPMD model substantially underestimates the contribution of delocalized states to the dynamics of the excess electron. However, with increasing solvent density, the RPMD model improves, nearly satisfying analytical continuation constraints at densities approaching those of typical liquids. In the high density regime, quantum dispersion substantially decreases the self-diffusion of the solvated electron. In this regime where the dynamics of the electron is strongly coupled to the dynamics of the atoms in the fluid, trajectories that can reveal diffusive motion of the electron are long in comparison to {beta}{h_bar}.
Characterizing Flow in Oil Reservoir Rock Using Smooth Particle Hydrodynamics
Holmes, David W.
In this paper, a 3D Smooth Particle Hydrodynamics (SPH) simulator for modeling grain scale fluid flow in porous rock is presented. The versatility of the SPH method has driven its use in increasingly complex areas of flow ...
Application of convolution and average pressure approximation for solving non-linear flow problems. constant pressure inner boundary condition for gas flow�
Zhakupov, Mansur
The accurate description of fluid flow through porous media allows an engineer to properly analyze past behavior and predict future reservoir performance. In particular, appropriate mathematical models which describe fluid ...
CFD modeling of commercial-scale entrained-flow coal gasifiers
Ma, J.; Zitney, S.
Optimization of an advanced coal-fired integrated gasification combined cycle system requires an accurate numerical prediction of gasifier performance. Computational fluid dynamics (CFD) has been used to model the turbulent multiphase reacting flow inside commercial-scale entrained-flow coal gasifiers. Due to the complexity of the physical and chemical processes involved, the accuracy of sub-models requires further improvement. Built upon a previously developed CFD model for entrained-flow gasification, the advanced physical and chemical sub-models presented in this paper include a moisture vaporization model with consideration of high mass transfer rate and a coal devolatilization model with more species to represent coal volatiles and the heating rate effect on volatile yield. The global gas phase reaction kinetics is also carefully selected. To predict a reasonable peak temperature of the coal/O{sub 2} flame inside an entrained-flow gasifier, the reserve reaction of H{sub 2} oxidation is included in the gas phase reaction model. The enhanced CFD model is applied to simulate two typical commercial-scale oxygen-blown entrained-flow configurations including a single-stage down-fired gasifier and a two-stage up-fired gasifier. The CFD results are reasonable in terms of predicted carbon conversion, syngas exit temperature, and syngas exit composition. The predicted profiles of velocity, temperature, and species mole fractions inside the entrained-flow gasifier models show trends similar to those observed in a diffusion-type flame. The predicted distributions of mole fractions of major species inside both gasifiers can be explained by the heterogeneous combustion and gasification reactions and the homogeneous gas phase reactions. It was also found that the syngas compositions at the CFD model exits are not in chemical equilibrium, indicating the kinetics for both heterogeneous and gas phase homogeneous reactions are important. Overall, the results achieved here indicate that the gasifier models reported in this paper are reliable and accurate enough to be incorporated into process/CFD co-simulations of IGCC power plants for system-wide design and optimization.
Y. Wu; S. Mukhopadhyay; K. Zhang; G.S. Bodvarsson
A mountain-scale, thermal-hydrologic (TH) numerical model is developed for investigating unsaturated flow behavior in response to decay heat from the radioactive waste repository at Yucca Mountain, Nevada, USA. The TH model, consisting of three-dimensional (3-D) representations of the unsaturated zone, is based on the current repository design, drift layout, and thermal loading scenario under estimated current and future climate conditions. More specifically, the TH model implements the current geological framework and hydrogeological conceptual models, and incorporates the most updated, best-estimated input parameters. This mountain-scale TH model simulates the coupled TH processes related to mountain-scale multiphase fluid flow, and evaluates the impact of radioactive waste heat on the hydrogeological system, including thermally perturbed liquid saturation, gas- and liquid-phase fluxes, and water and rock temperature elevations, as well as the changes in water flux driven by evaporation/condensation processes and drainage between drifts. For a better description of the ambient geothermal condition of the unsaturated zone system, the TH model is first calibrated against measured borehole temperature data. The ambient temperature calibration provides the necessary surface and water table boundary as well as initial conditions. Then, the TH model is used to obtain scientific understanding of TH processes in the Yucca Mountain unsaturated zone under the designed schedule of repository thermal load.
Ion boundary conditions in semi-infinite fluid models of electron beam-plasma interaction
Levko, Dmitry [LAPLACE (Laboratoire Plasma et Conversion d'Energie), Universite de Toulouse, UPS, INPT Toulouse, 118 route de Narbonne, F-31062 Toulouse cedex 9 (France)
The modified Bohm criterion is derived for the plasma consisting of the monoenergetic electron beam and thermal electrons. This criterion allows us to define the accurate ion boundary conditions for semi-infinite collisionless fluid models of electron beam�plasma interaction. In the absence of electron beam, these boundary conditions give the classical sheath parameters. When the monoenergetic electron beam propagates through the plasma, the fluid model with proposed boundary conditions gives the results, which are in qualitative agreement with the results obtained earlier in M. Sharifian and B. Shokri, Phys. Plasmas 14, 093503 (2007). However, dynamics and parameters of the plasma sheath are different.
Energy stability analysis for a hybrid fluid-kinetic plasma model
Philip J. Morrison; Emanuele Tassi; Cesare Tronci
In plasma physics, a hybrid fluid-kinetic model is composed of a magnetohydrodynamics (MHD) part that describes a bulk fluid component and a Vlasov kinetic theory part that describes an energetic plasma component. While most hybrid models in the plasma literature are non-Hamiltonian, this paper investigates a recent Hamiltonian variant in its two-dimensional configuration. The corresponding Hamiltonian structure is described along with its Casimir invariants. Then, the energy-Casimir method is used to derive explicit sufficient stability conditions, which imply a stable spectrum and suggest nonlinear stability.
Doughty, Christine
Fluid Heat Storage Systems in the Ground. Extraction ofof the storage aquifer lies 40 m below the ground surface,water storage. The influence of regional ground water flow
Modeling of three-dimensional viscoelastic flows with free surfaces using a finite element method
Adrian, David Joseph
A framework and code have been developed to simulate fiber and film processes; the code can handle three-dimensional, isothermal, incompressible, creeping flow of a Giesekus fluid with free surfaces at infinite capillary ...
A flowing plasma model to describe drift waves in a cylindrical helicon discharge
Chang, L.; Hole, M. J.; Corr, C. S. [Plasma Research Laboratory, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia)
A two-fluid model developed originally to describe wave oscillations in the vacuum arc centrifuge, a cylindrical, rapidly rotating, low temperature, and confined plasma column, is applied to interpret plasma oscillations in a RF generated linear magnetized plasma [WOMBAT (waves on magnetized beams and turbulence)], with similar density and field strength. Compared to typical centrifuge plasmas, WOMBAT plasmas have slower normalized rotation frequency, lower temperature, and lower axial velocity. Despite these differences, the two-fluid model provides a consistent description of the WOMBAT plasma configuration and yields qualitative agreement between measured and predicted wave oscillation frequencies with axial field strength. In addition, the radial profile of the density perturbation predicted by this model is consistent with the data. Parameter scans show that the dispersion curve is sensitive to the axial field strength and the electron temperature, and the dependence of oscillation frequency with electron temperature matches the experiment. These results consolidate earlier claims that the density and floating potential oscillations are a resistive drift mode, driven by the density gradient. To our knowledge, this is the first detailed physics model of flowing plasmas in the diffusion region away from the RF source. Possible extensions to the model, including temperature nonuniformity and magnetic field oscillations, are also discussed.
Stress and Fluid-Flow Interaction for the Coso Geothermal Field...
Field Derived from 3D Numerical Models Abstract The efficiency of geothermal energy production at the Coso Geothermal Field in eastern California is reliant on the knowledge...
Equilibrium and volumetric data and model development of coal fluids
Robinson, R.L. Jr.; Gasem, K.A.M.; Park, J.
The long term goal of our efforts is to develop accurate predictive methods for description of equilibrium phase properties for a variety of types of mixtures and operating conditions. The specific objectives of the work specified herein include: (1) development of an experimental facility having the capability to provide data on equilibrium phase compositions (solubilities) and liquid densities, and doing so with greater accuracy and speed than our previous facility, (2) measurement of equilibrium phase properties for systematically-selected mixtures-specifically those containing important solute gases (such as hydrogen, carbon monoxide, methane, ethane, carbonyl sulfide, ammonia) in a series of heavy paraffinic, naphthenic and aromatic solvents (e.g., n-decane, n-eicosane, n-octacosane, n-hexatriacontane, cyclohexane, Decalin, perhydrophenanthrene, perhydropyrene, benzene, naphthalene, phenanthrene, pyrene), (3) testing/development of correlation frameworks for representing the phase behavior of fluids of the type encountered in coal conversion processes, and (4) generalization of parameters in the correlation frameworks to enable accurate predictions for systems of the type studied, permitting predictions to be made for systems and conditions other than those for which experimental data are available.
Wetting and free surface flow modeling for potting and encapsulation.
Brooks, Carlton, F.; Brooks, Michael J. (Los Alamos National Laboratory, Los Alamos, NM); Graham, Alan Lyman (Los Alamos National Laboratory, Los Alamos, NM); Noble, David F. (David Frederick) (.; )); Notz, Patrick K.; Hopkins, Matthew Morgan; Castaneda, Jaime N.; Mahoney, Leo James (Kansas City Plant, Kansas City, MO); Baer, Thomas A.; Berchtold, Kathryn (Los Alamos National Laboratory, Los Alamos, NM); Adolf, Douglas Brian; Wilkes, Edward Dean; Rao, Rekha Ranjana; Givler, Richard C.; Sun, Amy Cha-Tien; Cote, Raymond O.; Mondy, Lisa Ann; Grillet, Anne Mary; Kraynik, Andrew Michael
As part of an effort to reduce costs and improve quality control in encapsulation and potting processes the Technology Initiative Project ''Defect Free Manufacturing and Assembly'' has completed a computational modeling study of flows representative of those seen in these processes. Flow solutions are obtained using a coupled, finite-element-based, numerical method based on the GOMA/ARIA suite of Sandia flow solvers. The evolution of the free surface is solved with an advanced level set algorithm. This approach incorporates novel methods for representing surface tension and wetting forces that affect the evolution of the free surface. In addition, two commercially available codes, ProCAST and MOLDFLOW, are also used on geometries representing encapsulation processes at the Kansas City Plant. Visual observations of the flow in several geometries are recorded in the laboratory and compared to the models. Wetting properties for the materials in these experiments are measured using a unique flowthrough goniometer.
Cost and Performance Model for Redox Flow Batteries
Viswanathan, Vilayanur V.; Crawford, Aladsair J.; Stephenson, David E.; Kim, Soowhan; Wang, Wei; Li, Bin; Coffey, Greg W.; Thomsen, Edwin C.; Graff, Gordon L.; Balducci, Patrick J.; Kintner-Meyer, Michael CW; Sprenkle, Vincent L.
A cost model was developed for all vanadium and iron-vanadium redox flow batteries. Electrochemical performance modeling was done to estimate stack performance at various power densities as a function of state of charge. This was supplemented with a shunt current model and a pumping loss model to estimate actual system efficiency. The operating parameters such as power density, flow rates and design parameters such as electrode aspect ratio, electrolyte flow channel dimensions were adjusted to maximize efficiency and minimize capital costs. Detailed cost estimates were obtained from various vendors to calculate cost estimates for present, realistic and optimistic scenarios. The main drivers for cost reduction for various chemistries were identified as a function of the energy to power ratio of the storage system. Levelized cost analysis further guided suitability of various chemistries for different applications.
A Model of Job and Worker Flows Nobuhiro Kiyotaki
A Model of Job and Worker Flows Nobuhiro Kiyotaki Princeton University Ricardo Lagos New York University August 17, 2007 Abstract We develop an equilibrium search model that incorporates job-to-job transitions, exhibits instances of replacement hiring, and conceptually distinguishes between job and worker
155: Numerical Models of Groundwater Flow and Transport
Sorek, Shaul
155: Numerical Models of Groundwater Flow and Transport EKKEHARD HOLZBECHER1 AND SHAUL SOREK2 1. #12;2402 GROUNDWATER Calibration as a task cannot be separated from the other tasks. Inverse modeling of the Negev, J. Blaustein Institutes for Desert Research, Sede Boker, Israel The article gives an introduction
Flows of Incompressible Newtonian and Generalized Newtonian Fluids over a Circular Cylinder
Klein, Kayla
of Work 1 1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Literature Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.3 Scope of Work... . . . . . . . . . . . . . . . . . . . . . . . . 10 2.3 Mathematical Model in R2, Explicit Form: BVP . . . . . . . . . . . . . . . 12 vi 2.4 Dimensionless Form of the Mathematical Model in R2 . . . . . . . . . . . 13 2.4.1 Constitutive Equations for [? ]: . . . . . . . . . . . . . . . . . . . . 14 2...
A Semi-Lagrangian approach for dilute non-collisional fluid-particle flows
Goudon, Thierry
of sandstorms, sediment transport, the "white water" produced by breaking waves [48], dispersion of ash during of dilute suspensions. The modelling is motivated by many applications ranging from industrial processes t represents time. In this modelling, at any position both phases can be present, and, assuming that particles
Locomotion in complex fluids: Integral theorems
Eric Lauga
The biological fluids encountered by self-propelled cells display complex microstructures and rheology. We consider here the general problem of low-Reynolds number locomotion in a complex fluid. {Building on classical work on the transport of particles in viscoelastic fluids,} we demonstrate how to mathematically derive three integral theorems relating the arbitrary motion of an isolated organism to its swimming kinematics {in a non-Newtonian fluid}. These theorems correspond to three situations of interest, namely (1) squirming motion in a linear viscoelastic fluid, (2) arbitrary surface deformation in a weakly non-Newtonian fluid, and (3) small-amplitude deformation in an arbitrarily non-Newtonian fluid. Our final results, valid for a wide-class of {swimmer geometry,} surface kinematics and constitutive models, at most require mathematical knowledge of a series of Newtonian flow problems, and will be useful to quantity the locomotion of biological and synthetic swimmers in complex environments.
A numerical study of steady fluid flow in the entry region of a straight circular tube
Crain, John Kee
region. The Basic Equations The flow under i nves ti gati on is governed by the Navier-Stokes equations p ? = F - . + uv Du Dt x ax p ? = F - @uv v, Dv a A 2 Dt y ay (2) Dw= F ma+ Dt w as and the continuity equation "u av aw + ? = p ay... + w D a a a a Ut = at ax ay as and 2 a2 a2 a2 ax2 ay2 as2 Expressed in cylindrical form, the previous equations become 2 P = Fr M + & v V r e D Ve 2aV Dt r " ar r2ae DVe V Ve 2aV V p + ? = Fe - ~a + u & Ve + r - e Dt r rae (2a) F -22+ pv V...
Peristaltic flow of a fluid in a porous channel: A study having relevance to flow of bile within ducts in a pathological state
S Maiti; J. C. Misra
The paper deals with a theoretical study of the transport of a fluid in a channel, which takes place by the phenomenon of peristalsis. A mathematical analysis of the said problem has been presented. The analysis involves the application of a suitable perturbation technique. The velocity profile and the critical pressure for the occurrence of reflux are investigated with particular emphasis by using appropriate numerical methods. The effects of various parameters, such as Reynolds number, pressure gradient, porosity parameter, Darcy number, slip parameter, amplitude ratio and wave number on velocity and critical pressure for reflux are investigated in detail. The computed results are compared with a previous analytical work and an experimental investigation reported earlier in existing scientific literatures. The results of the present study are in conformity to both of them. The study has got some relevance to the physiological flow of bile in the common bile duct in a pathological state. It reveals that in the presence of gallstones, bile velocity increases as the value of the porosity parameter increases, while the critical pressure for reflux decreases as porosity increases.
Impact of structured heterogeneities on reactive two-phase porous flow
Reeves, Daniel
Two-phase flow through heterogeneous media leads to scale-free distributions of irregularly shaped pockets of one fluid trapped within the other. Although reactions within these fluids are often modeled at the homogeneous ...
Two dimensional, two fluid model for sodium boiling in LMFBR fuel assemblies
Granziera, M.R.; Kazimi, M.S.
A two dimensional numerical model for the simulation of sodium boiling transient was developed using the two fluid set of conservation equations. A semiimplicit numerical differencing scheme capable of handling the problems associated with the ill-posedness implied by the complex characteristic roots of the two fluid problems was used, which took advantage of the dumping effect of the exchange terms. Of particular interest in the development of the model was the identification of the numerical problems caused by the strong disparity between the axial and radial dimensions of fuel assemblies. A solution to this problem was found which uses the particular geometry of fuel assemblies to accelerate the convergence of the iterative technique used in the model. Three sodium boiling experiments were simulated with the model, with good agreement between the experimental results and the model predictions.
Fluid Dynamics in Sucker Rod Pumps
Cutler, R.P.; Mansure, A.J.
Sucker rod pumps are installed in approximately 90% of all oil wells in the U.S. Although they have been widely used for decades, there are many issues regarding the fluid dynamics of the pump that have not been fully investigated. A project was conducted at Sandia National Laboratories to develop unimproved understanding of the fluid dynamics inside a sucker rod pump. A mathematical flow model was developed to predict pressures in any pump component or an entire pump under single-phase fluid and pumping conditions. Laboratory flow tests were conducted on instrumented individual pump components and on a complete pump to verify and refine the model. The mathematical model was then converted to a Visual Basic program to allow easy input of fluid, geometry and pump parameters and to generate output plots. Examples of issues affecting pump performance investigated with the model include the effects of viscosity, surface roughness, valve design details, plunger and valve pressure differentials, and pumping rate.
One- and two-dimensional Stirling machine simulation using experimentally generated reversing flow turbuulence models
Goldberg, L.F. [Univ. of Minnesota, Minneapolis, MN (United States)
The activities described in this report do not constitute a continuum but rather a series of linked smaller investigations in the general area of one- and two-dimensional Stirling machine simulation. The initial impetus for these investigations was the development and construction of the Mechanical Engineering Test Rig (METR) under a grant awarded by NASA to Dr. Terry Simon at the Department of Mechanical Engineering, University of Minnesota. The purpose of the METR is to provide experimental data on oscillating turbulent flows in Stirling machine working fluid flow path components (heater, cooler, regenerator, etc.) with particular emphasis on laminar/turbulent flow transitions. Hence, the initial goals for the grant awarded by NASA were, broadly, to provide computer simulation backup for the design of the METR and to analyze the results produced. This was envisaged in two phases: First, to apply an existing one-dimensional Stirling machine simulation code to the METR and second, to adapt a two-dimensional fluid mechanics code which had been developed for simulating high Rayleigh number buoyant cavity flows to the METR. The key aspect of this latter component was the development of an appropriate turbulence model suitable for generalized application to Stirling simulation. A final-step was then to apply the two-dimensional code to an existing Stirling machine for which adequate experimental data exist. The work described herein was carried out over a period of three years on a part-time basis. Forty percent of the first year`s funding was provided as a match to the NASA funds by the Underground Space Center, University of Minnesota, which also made its computing facilities available to the project at no charge.
Numerical modeling of multiphase plumes: a comparative study between two-fluid and mixed-fluid integral models
Bhaumik, Tirtharaj
-field effects of a multiphase plume of liquid CO2 droplets in ocean water finds potential in estimating the environmental risks involved due to deep-ocean sequestration of greenhouse gases like carbon dioxide, which is one of the proposed alternatives (Liro... for the diffuser orifice diameter, air-flow rate and the number of such ports necessary to dissolve a measured quantity of air in a given time of operation will also be studied. 3.3. Case 3: CO2 Sequestration in the Ocean Sequestration of carbon dioxide and other...
aqueous magnetic fluids: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
of the fluid layer, and iii) has a maximum at a driving frequency of about 3 kHz. The pumping speed can be estimated with a two-dimensional flow model. Krauss, R; Reimann, B;...
An improved multiscale model for dilute turbulent gas particle flows based on the equilibration of energy concept
Xu, Ying
Many particle-laden flows in engineering applications involve turbulent gas flows. Modeling multiphase turbulent flows is an important research topic with applications in fluidized beds and particle conveying. A predictive multiphase turbulence model can help CFD codes to be more useful for engineering applications, such as the scale-up in the design of circulating fluidized combustor and coal gasifications. In engineering applications, the particle volume fraction can vary from dilute (<10{sup -4}) to dense ({approx} 50%). It is reasonable to expect that multiphase turbulence models should at least satisfy some basic modeling and performance criteria and give reasonable predictions for the canonical problems in dilute particle-laden turbulent flows. In this research, a comparative assessment of predictions from Simonin and Ahmadi's turbulence models is performed with direct numerical simulation (DNS) for two canonical problems in particle-laden turbulent flows. Based on the comparative assessment, some criteria and the areas for model improvement are identified: (1) model for interphase TKE transfer, especially the time scale of interphase TKE transfer, and (2) correct prediction of TKE evolution with variation of particle Stokes number. Some deficiencies that are identified in the Simonin and Ahmadi models, limit the applicability. A new multiphase turbulence model, the Equilibration of Energy Model (EEM), is proposed in this work. In EEM, a multiscale interaction time scale is proposed to account for the interaction of a particle with a range of eddy sizes. EEM shows good agreement with the DNS results for particle-laden isotropic turbulence. For particle-laden homogeneous shear flows, model predictions from EEM can be further improved if the dissipation rate in fluid phase is modeled with more accuracy.
Modeling and Algorithmic Approaches to Constitutively-Complex, Microstructured Fluids
Miller, Gregory H.; Forest, Gregory
We present a new multiscale model for complex uids based on three scales: microscopic, kinetic, and continuum. We choose the microscopic level as Kramers' bead-rod model for polymers, which we describe as a system of stochastic di#11;erential equations with an implicit constraint formulation. The associated Fokker-Planck equation is then derived, and adiabatic elimination removes the fast momentum coordinates. Approached in this way, the kinetic level reduces to a dispersive drift equation. The continuum level is modeled with a #12;nite volume Godunov-projection algorithm. We demonstrate computation of viscoelastic stress divergence using this multiscale approach.
Soto, Enrique
This fluid dynamics video is an entry for the Gallery of Fluid Motion for the 66th Annual Meeting of the Fluid Dynamics Division of the American Physical Society. We show the curious behaviour of a light ball interacting with a liquid jet. For certain conditions, a ball can be suspended into a slightly inclined liquid jet. We studied this phenomenon using a high speed camera. The visualizations show that the object can be `juggled' for a variety of flow conditions. A simple calculation showed that the ball remains at a stable position due to a Bernoulli-like effect. The phenomenon is very stable and easy to reproduce.
Rossby and Drift Wave Turbulence and Zonal Flows: the Charney-Hasegawa-Mima model and its extensions
Colm Connaughton; Sergey Nazarenko; Brenda Quinn
A detailed study of the Charney-Hasegawa-Mima model and its extensions is presented. These simple nonlinear partial differential equations suggested for both Rossby waves in the atmosphere and also drift waves in a magnetically-confined plasma exhibit some remarkable and nontrivial properties, which in their qualitative form survive in more realistic and complicated models, and as such form a conceptual basis for understanding the turbulence and zonal flow dynamics in real plasma and geophysical systems. Two idealised scenarios of generation of zonal flows by small-scale turbulence are explored: a modulational instability and turbulent cascades. A detailed study of the generation of zonal flows by the modulational instability reveals that the dynamics of this zonal flow generation mechanism differ widely depending on the initial degree of nonlinearity. A numerical proof is provided for the extra invariant in Rossby and drift wave turbulence -zonostrophy and the invariant cascades are shown to be characterised by the zonostrophy pushing the energy to the zonal scales. A small scale instability forcing applied to the model demonstrates the well-known drift wave - zonal flow feedback loop in which the turbulence which initially leads to the zonal flow creation, is completely suppressed and the zonal flows saturate. The turbulence spectrum is shown to diffuse in a manner which has been mathematically predicted. The insights gained from this simple model could provide a basis for equivalent studies in more sophisticated plasma and geophysical fluid dynamics models in an effort to fully understand the zonal flow generation, the turbulent transport suppression and the zonal flow saturation processes in both the plasma and geophysical contexts as well as other wave and turbulence systems where order evolves from chaos.
Numerical Modeling of Hydro-acoustic Waves In Weakly Compressible Fluid Ali Abdolali1,2
Kirby, James T.
Numerical Modeling of Hydro-acoustic Waves In Weakly Compressible Fluid Ali Abdolali1,2 , James T of Civil Engineering, University of Roma Tre Low-frequency hydro-acoustic waves are precursors of tsunamis. Detection of hydro-acoustic waves generated due to the water column compression triggered by sudden seabed
Derivation and Implementation of Hybrid Fluid/Kinetic Model for Fusion Plasmas
Held, E. D.
This is a final report for Dr. Eric Held�s Junior Faculty in Plasmas Physics grant entitled, �Derivation and Implementation of Hybrid Fluid/Kinetic Model for Fusion Plasmas�. Progress over the three years and six months of this project included work on analytical and numerical fronts.
Experimental Validation of a Computational Fluid Dynamics Model for IAQ applications in Ice Rink Arenas
Chen, Qingyan "Yan"
1 Experimental Validation of a Computational Fluid Dynamics Model for IAQ applications in Ice Rink, USA, Fax: 617-432-4122, Abstract Many ice rink arenas have ice resurfacing equipment that uses fossil temperature distributions in ice rinks. The numerical results agree reasonably with the corresponding
Technical Note Design and modeling of a fluid-based micro-scale electrocaloric
McGaughey, Alan
Technical Note Design and modeling of a fluid-based micro-scale electrocaloric refrigeration system a c t A refrigeration system composed of silicon MEMS cooling elements is designed based. The main advantage of EC cooling over magnet- ocaloric cooling (which operates on an analogous principle