text: /*!
   *  \file SphericalAreaVolumeRatio.h
   *    \brief Auxillary kernel to calculate the area-to-volume ratio of spherical particles
   *    \details This file is responsible for calculating the area-to-volume ratio
   *            for spherical particles of a particular size. The purpose is to have
   *            these values automatically calculated for usage in the 'FilmMassTransfer'
   *            or similar mass or energy transfer functions.
   *
   *  \author Austin Ladshaw
   *  \date 09/14/2021
   *  \copyright This kernel was designed and built at Oak Ridge National
   *              Laboratory by Austin Ladshaw for research in catalyst
   *              performance for new vehicle technologies.
   *
   *               Austin Ladshaw does not claim any ownership or copyright to the
   *               MOOSE framework in which these kernels are constructed, only
   *               the kernels themselves. The MOOSE framework copyright is held
   *               by the Battelle Energy Alliance, LLC (c) 2010, all rights reserved.
   */
  
  /****************************************************************/
  /*               DO NOT MODIFY THIS HEADER                      */
  /* MOOSE - Multiphysics Object Oriented Simulation Environment  */
  /*                                                              */
  /*           (c) 2010 Battelle Energy Alliance, LLC             */
  /*                   ALL RIGHTS RESERVED                        */
  /*                                                              */
  /*          Prepared by Battelle Energy Alliance, LLC           */
  /*            Under Contract No. DE-AC07-05ID14517              */
  /*            With the U. S. Department of Energy               */
  /*                                                              */
  /*            See COPYRIGHT for full restrictions               */
  /****************************************************************/
  
  #pragma once
  
  #include "AuxKernel.h"
  
  /// SphericalAreaVolumeRatio class inherits from AuxKernel
  /** This class object creates an AuxKernel for use in the MOOSE framework. The AuxKernel will
      calculate the variable as a ratio of spherical area to volume given a diameter. */
  class SphericalAreaVolumeRatio : public AuxKernel
  {
  public:
      /// Required new syntax for InputParameters
      static InputParameters validParams();
  
      /// Standard MOOSE public constructor
      SphericalAreaVolumeRatio(const InputParameters & parameters);
  
  protected:
      /// Required MOOSE function override
      /** This is the function that is called by the MOOSE framework when a calculation of the total
          system pressure is needed. You are required to override this function for any inherited
          AuxKernel. */
      virtual Real computeValue() override;
  
  private:
      Real _particle_diameter;        ///< Diameter of the particle for which the ratio is calculated (L)
      const VariableValue & _bulk_porosity;       ///< Ratio of channel volume to total volume
      bool _PerSolidsVolume;     ///< Boolean to determine if ratio to be calculated is per solid volume or per total volume
  
  };
  