KKSPhaseConcentration.C

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//* This file is part of the MOOSE framework
//* https://mooseframework.inl.gov
//*
//* All rights reserved, see COPYRIGHT for full restrictions
//* https://github.com/idaholab/moose/blob/master/COPYRIGHT
//*
//* Licensed under LGPL 2.1, please see LICENSE for details
//* https://www.gnu.org/licenses/lgpl-2.1.html
 
#include "KKSPhaseConcentration.h"
 
registerMooseObject("PhaseFieldApp", KKSPhaseConcentration);
 
InputParameters
KKSPhaseConcentration::validParams()
{
  InputParameters params = Kernel::validParams();
  params.addClassDescription("KKS model kernel to enforce the decomposition of concentration into "
                             "phase concentration  $(1-h(\\eta))c_a + h(\\eta)c_b - c = 0$. The "
                             "non-linear variable of this kernel is $c_b$.");
  params.addRequiredCoupledVar("ca", "Phase a concentration");
  params.addRequiredCoupledVar("c", "Real concentration");
  params.addRequiredCoupledVar("eta", "Phase a/b order parameter");
  params.addParam<MaterialPropertyName>(
      "h_name", "h", "Base name for the switching function h(eta)");
  return params;
}
 
// Phase interpolation func
KKSPhaseConcentration::KKSPhaseConcentration(const InputParameters & parameters)
  : DerivativeMaterialInterface<Kernel>(parameters),
    _ca(coupledValue("ca")),
    _ca_var(coupled("ca")),
    _c(coupledValue("c")),
    _c_var(coupled("c")),
    _eta(coupledValue("eta")),
    _eta_var(coupled("eta")),
    _prop_h(getMaterialProperty<Real>("h_name")),
    _prop_dh(getMaterialPropertyDerivative<Real>("h_name", coupledName("eta", 0)))
{
}
 
Real
KKSPhaseConcentration::computeQpResidual()
{
  // R = (1-h(eta))*ca + h(eta)*cb - c
  return _test[_i][_qp] * ((1.0 - _prop_h[_qp]) * _ca[_qp] + _prop_h[_qp] * _u[_qp] - _c[_qp]);
}
 
Real
KKSPhaseConcentration::computeQpJacobian()
{
  return _test[_i][_qp] * _prop_h[_qp] * _phi[_j][_qp];
}
 
Real
KKSPhaseConcentration::computeQpOffDiagJacobian(unsigned int jvar)
{
  if (jvar == _ca_var)
    return _test[_i][_qp] * (1.0 - _prop_h[_qp]) * _phi[_j][_qp];
 
  else if (jvar == _c_var)
    return -_test[_i][_qp] * _phi[_j][_qp];
 
  else if (jvar == _eta_var)
    return _test[_i][_qp] * (_u[_qp] - _ca[_qp]) * _prop_dh[_qp] * _phi[_j][_qp];
 
  return 0.0;
}