text: /*!
   *  \file MonolithAreaVolumeRatio.h
   *    \brief Auxillary kernel to calculate the area-to-volume ratio of monolith channels
   *    \details This file is responsible for calculating the area-to-volume ratio
   *            for monolith channels based on the bulk channel volume to total volume
   *            ratio for the reactor (i.e., bulk porosity) and the cell density of
   *            the monolith (cells per total face area). Usits on output will be same
   *            unit basis on input.
   *
   *  \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.
   */
  
  #pragma once
  
  #include "AuxKernel.h"
  
  /// MonolithAreaVolumeRatio class inherits from AuxKernel
  class MonolithAreaVolumeRatio : public AuxKernel
  {
  public:
      /// Required new syntax for InputParameters
      static InputParameters validParams();
  
      /// Standard MOOSE public constructor
      MonolithAreaVolumeRatio(const InputParameters & parameters);
  
  protected:
      /// Required MOOSE function override
      virtual Real computeValue() override;
  
  private:
      Real _cell_density;        ///< Cell density of the monolith (cells per total face area)
      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
  
  };
  