Testing new turbine cooling schemes at engine conditions becomes cost prohibitive as gas-path temperatures increase. As a result, turbine components are simulated in a laboratory with a large-scale model that is sized and constructed out of a selected material so that the Biot number is matched between the laboratory and engine conditions. Furthermore, the experimental temperatures are lower, so the surface temperature that the metal component would experience is scaled via the overall cooling effectiveness, $ϕ$. Properly measuring $ϕ$ requires that the relevant flow physics must be matched, thus the Reynolds numbers is matched—both those of the freestream and the coolant, as well as the other scaling parameters, such as the mass flux, momentum flux, and velocity ratios. However, if the coolant-to-freestream density ratio does not match that of the engine condition, the mass flux, momentum flux, coolant and freestream Reynolds numbers, and coolant-to-freestream velocity ratios cannot be matched simultaneously to the engine condition. Furthermore, the coolant thermal transfer properties are unaccounted for in these parameters, despite their large influence on the resultant overall effectiveness. While much research has focused on the effects of the coolant-to-freestream density ratio, this study examines the influence of other thermodynamic properties, in particular the specific heat, which differ substantially between experimental and engine conditions. This study demonstrates the influence of various coolant properties on the overall effectiveness distribution on a leading edge by selectively matching $M$, $I$, and $ACR$ with air, argon, and carbon dioxide coolants.

## References

References
1.
Albert
,
J. E.
,
Bogard
,
D. G.
, and
Cunha
,
F.
,
2004
, “
,”
ASME
Paper No. GT2004-53998.
2.
Pietrzyk
,
J. R.
,
Bogard
,
D. G.
, and
Crawford
,
M. E.
,
1990
, “
Effects of Density Ratio on the Hydrodynamics of Film Cooling
,”
ASME J. Turbomach.
,
112
(
3
), pp.
437
443
.
3.
Thole
,
K. A.
,
Sinha
,
A. K.
,
Bogard
,
D. G.
, and
Crawford
,
M. E.
,
1992
, “
Mean Temperature Measurements of Jets With a Crossflow for Gas Turbine Film Cooling Application
,”
Third International Symposium on Transport Phenomena and Dynamics of Rotating Machinery
(
ISROMAC-3
), Honolulu, HI, Apr. 1–4, pp.
69
85
4.
Sinha
,
A. K.
,
Bogard
,
D. G.
, and
Crawford
,
M. E.
,
1991
, “
Film Cooling Downstream of a Single Row of Holes With Variable Density Ratio
,”
ASME J. Turbomach.
,
113
(
3
), pp.
442
449
.
5.
Wiese
,
C. J.
,
Rutledge
,
J. L.
, and
Polanka
,
M. D.
,
2018
, “
Experimental Evaluation of Thermal and Mass Transfer Techniques to Measure Adiabatic Effectiveness With Various Coolant to Freestream Property Ratios
,”
ASME J. Turbomach.
,
140
(
2
), p.
021001
.
6.
Rutledge
,
J. L.
, and
Polanka
,
M. D.
,
2014
, “
Computational Fluid Dynamics Evaluations of Unconventional Film Cooling Scaling Parameters on a Simulated Turbine Blade Leading Edge
,”
ASME J. Turbomach.
,
136
(
10
), p.
101006
.
7.
Dyson
,
T. E.
,
Bogard
,
D. G.
,
Piggush
,
J. D.
, and
Kohli
,
A.
,
2013
, “
Overall Effectiveness for a Film Cooled Turbine Blade Leading Edge With Varying Hole Pitch
,”
ASME J. Turbomach.
,
135
(
3
), p.
031011
.
8.
Dyson
,
T. E.
,
Bogard
,
D. G.
,
McClintic
,
J. W.
, and
,
S. D.
,
2013
, “
Adiabatic and Overall Effectiveness for a Fully Cooled Turbine Vane
,”
ASME
Turbo Paper No. GT2013-94928.
9.
,
S. V.
,
Ou
,
S.
, and
Rivir
,
R. B.
,
2004
, “
A Transient Infrared Thermography Method for Simultaneous Film Cooling Effectiveness and Heat Transfer Coefficient Measurements From a Single Test
,”
ASME J. Turbomach.
,
126
(
4
), pp.
597
603
.
10.
Bryant
,
C. E.
,
Wiese
,
C. J.
,
Rutledge
,
J. L.
, and
Polanka
,
M. D.
,
2018
, “
Experimental Evaluations of the Relative Contributions to Overall Effectiveness in Turbine Blade Leading Edge Cooling
,”
ASME
Paper No. GT2018-75334.
11.
Rutledge
,
J. L.
,
King
,
P. I.
, and
Rivir
,
R.
,
2012
, “
,”
ASME J. Eng. Gas Turbines Power
,
134
(7), p.
071901
.
12.
Bryant
,
C. E.
,
2017
, “
Relative Contributions to Overall Effectiveness in Gas Turbine Cooling
,” M.S. thesis, Air Force Institute of Technology, Wright-Patterson AFB, OH.
13.
Touloukian
,
Y. S.
,
Saxena
,
S. C.
, and
Hestermans
,
P.
,
1970
, “
Thermophysical Properties of Matter, 11: Viscosity
,”
Nonmetallic Gases and Liquids
,
IFI/Plenum
,
New York
.
14.
Touloukian
,
Y. S.
, and
Makita
,
T.
,
1970
, “
Thermophysical Properties of Matter, 6: Specific Heat
,”
Nonmetallic Gases and Liquids
,
IFI/Plenum
,
New York
.
15.
Touloukian
,
Y. S.
,
Liley
,
P. E.
, and
Saxena
,
S. C.
,
1970
, “
Thermophysical Properties of Matter, 3: Thermal Conductivity
,”
Nonmetallic Gases and Liquids
,
IFI/Plenum
,
New York
.
16.
Kline
,
S. J.
, and
McClintock
,
F. A.
,
1953
, “
Describing Uncertainties in Single-Sample Experiments
,”
Mech. Eng.
,
75
(
1
), pp.
3
8
.
17.
Rutledge
,
J. L.
,
Polanka
,
M. D.
, and
Bogard
,
D. G.
,
2015
, “
The $Δϕ$ Method of Evaluating Overall Film Cooling Performance
,”
ASME
Paper No. GT2015-43288.
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