Line data    Source code

       1             : //* This file is part of the MOOSE framework
       2             : //* https://mooseframework.inl.gov
       3             : //*
       4             : //* All rights reserved, see COPYRIGHT for full restrictions
       5             : //* https://github.com/idaholab/moose/blob/master/COPYRIGHT
       6             : //*
       7             : //* Licensed under LGPL 2.1, please see LICENSE for details
       8             : //* https://www.gnu.org/licenses/lgpl-2.1.html
       9             : 
      10             : #pragma once
      11             : 
      12             : #include "KokkosIntegratedBC.h"
      13             : 
      14             : /**
      15             :  * Implements a simple Vacuum BC for neutron diffusion on the boundary.
      16             :  * Vacuum BC is defined as \f$ D\frac{du}{dn}+\frac{u}{2} = 0\f$, where u is neutron flux.
      17             :  * Hence, \f$ D\frac{du}{dn}=-\frac{u}{2} \f$ and \f$ -\frac{u}{2} \f$ is substituted into
      18             :  * the Neumann BC term produced from integrating the diffusion operator by parts.
      19             :  */
      20             : class KokkosVacuumBC final : public Moose::Kokkos::IntegratedBC<KokkosVacuumBC>
      21             : {
      22             : public:
      23             :   static InputParameters validParams();
      24             : 
      25             :   KokkosVacuumBC(const InputParameters & parameters);
      26             : 
      27             :   KOKKOS_FUNCTION Real computeQpResidual(const unsigned int i,
      28             :                                          const unsigned int qp,
      29             :                                          ResidualDatum & datum) const;
      30             :   KOKKOS_FUNCTION Real computeQpJacobian(const unsigned int i,
      31             :                                          const unsigned int j,
      32             :                                          const unsigned int qp,
      33             :                                          ResidualDatum & datum) const;
      34             : 
      35             : private:
      36             :   /// Ratio of u to du/dn
      37             :   const Real _alpha;
      38             : };
      39             : 
      40             : KOKKOS_FUNCTION inline Real
      41       13200 : KokkosVacuumBC::computeQpResidual(const unsigned int i,
      42             :                                   const unsigned int qp,
      43             :                                   ResidualDatum & datum) const
      44             : {
      45       13200 :   return _test(datum, i, qp) * _alpha * _u(datum, qp) / 2.;
      46             : }
      47             : 
      48             : KOKKOS_FUNCTION inline Real
      49        3840 : KokkosVacuumBC::computeQpJacobian(const unsigned int i,
      50             :                                   const unsigned int j,
      51             :                                   const unsigned int qp,
      52             :                                   ResidualDatum & datum) const
      53             : {
      54        3840 :   return _test(datum, i, qp) * _alpha * _phi(datum, j, qp) / 2.;
      55             : }