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             : #include "ThermoDiffusion.h"
      11             : 
      12             : registerMooseObject("MiscApp", ThermoDiffusion);
      13             : 
      14             : InputParameters
      15          38 : ThermoDiffusion::validParams()
      16             : {
      17          38 :   InputParameters params = Kernel::validParams();
      18          76 :   params.addRequiredCoupledVar("temp", "Coupled temperature");
      19          76 :   params.addParam<Real>("gas_constant", 8.3144621, "Gas constant");
      20          76 :   params.addParam<std::string>(
      21             :       "heat_of_transport", "heat_of_transport", "Property name for the heat of transport.");
      22          76 :   params.addParam<std::string>(
      23             :       "mass_diffusivity", "mass_diffusivity", "Property name for the diffusivity.");
      24             : 
      25          38 :   params.addClassDescription("Kernel for thermo-diffusion (Soret effect, thermophoresis, etc.)");
      26          38 :   return params;
      27           0 : }
      28             : 
      29          20 : ThermoDiffusion::ThermoDiffusion(const InputParameters & parameters)
      30             :   : Kernel(parameters),
      31          20 :     _temperature(coupledValue("temp")),
      32          20 :     _grad_temperature(coupledGradient("temp")),
      33          40 :     _mass_diffusivity(getMaterialProperty<Real>(getParam<std::string>("mass_diffusivity"))),
      34          40 :     _heat_of_transport(getMaterialProperty<Real>(getParam<std::string>("heat_of_transport"))),
      35          40 :     _gas_constant(getParam<Real>("gas_constant")),
      36          40 :     _temperature_index(coupled("temp"))
      37             : {
      38          20 : }
      39             : 
      40             : RealGradient
      41      130800 : ThermoDiffusion::thermoDiffusionVelocity() const
      42             : {
      43             :   // The thermo-diffusion term looks like grad( v * C ) where v is like a diffusive
      44             :   // velocity. If the concentration C does not couple back into the heat equation,
      45             :   // then the one-way coupling of temperature means that thermo-diffusion of C
      46             :   // behaves like advection. Then v is the velocity:
      47             :   //
      48             :   //   v = D Qstar grad(T) / ( R T^2 )
      49             :   //
      50      130800 :   Real coeff = _mass_diffusivity[_qp] * _heat_of_transport[_qp] /
      51      130800 :                (_gas_constant * _temperature[_qp] * _temperature[_qp]);
      52      130800 :   return coeff * _grad_temperature[_qp];
      53             : }
      54             : 
      55             : Real
      56      105200 : ThermoDiffusion::computeQpResidual()
      57             : {
      58      105200 :   return thermoDiffusionVelocity() * _u[_qp] * _grad_test[_i][_qp];
      59             : }
      60             : 
      61             : Real
      62       25600 : ThermoDiffusion::computeQpJacobian()
      63             : {
      64       25600 :   return thermoDiffusionVelocity() * _phi[_j][_qp] * _grad_test[_i][_qp];
      65             : }
      66             : 
      67             : Real
      68           0 : ThermoDiffusion::computeQpOffDiagJacobian(unsigned int jvar)
      69             : {
      70           0 :   if (jvar == _temperature_index)
      71             :   {
      72           0 :     Real coeff = _mass_diffusivity[_qp] * _heat_of_transport[_qp] /
      73           0 :                  (_gas_constant * _temperature[_qp] * _temperature[_qp]);
      74           0 :     return coeff * _grad_test[_i][_qp] * _u[_qp] *
      75           0 :            (_grad_phi[_j][_qp] - 2 * _phi[_j][_qp] * _grad_temperature[_qp] / _temperature[_qp]);
      76             :   }
      77             :   return 0;
      78             : }