SLKKSSum Class Reference

Enforce the sum of sublattice concentrations to a given phase concentration. More...

#include <SLKKSSum.h>

Inheritance diagram for SLKKSSum:

Public Types
typedef std::vector< int >	JvarMap

Public Member Functions
	SLKKSSum (const InputParameters &parameters)
virtual void	computeOffDiagJacobian (unsigned int jvar) override
unsigned int	mapJvarToCvar (unsigned int jvar)
int	mapJvarToCvar (unsigned int jvar, const JvarMap &jvar_map)
bool	mapJvarToCvar (unsigned int jvar, unsigned int &cvar)
const JvarMap &	getJvarMap ()
const JvarMap &	getParameterJvarMap (std::string parameter_name)

Static Public Member Functions
static InputParameters	validParams ()

Protected Member Functions
virtual Real	computeQpResidual ()
virtual Real	computeQpJacobian ()
virtual Real	computeQpOffDiagJacobian (unsigned int jvar)

Protected Attributes
Real	_a_u
	sublattice fraction for the sublattice B concentration represented by the kernel variable
const VariableValue &	_target
	AuxVariable to hold the target sum.
const unsigned int	_n_args
unsigned int	_ncs
	sublattice A variables
std::vector< const VariableValue * >	_cs
std::vector< Real >	_a_cs
const JvarMap &	_cs_map

Private Attributes
const std::size_t	_jvar_max_size
JvarMap	_jvar_map
std::map< std::string, JvarMap >	_jvar_local_map

Detailed Description

Enforce the sum of sublattice concentrations to a given phase concentration.

This is for test simulations to equilibrate the internal degrees of freedom in a phase with multiple sublattices. The total concentration is prescribed by an AuxVariable. D. Schwen et al. https://doi.org/10.1016/j.commatsci.2021.110466

Definition at line 22 of file SLKKSSum.h.

Constructor & Destructor Documentation

SLKKSSum()

SLKKSSum::SLKKSSum

(

const InputParameters &

parameters

)

Definition at line 28 of file SLKKSSum.C.

  : JvarMapKernelInterface<Kernel>(parameters),
    _ncs(coupledComponents("cs")),
    _cs(_ncs),
    _a_cs(getParam<std::vector<Real>>("as")),
    _cs_map(getParameterJvarMap("cs")),
    _a_u(getParam<Real>("a")),
    _target(coupledValue("sum"))
{
  if (_a_cs.size() != _ncs)
    paramError("as", "Specify one sublattice site fraction per sublattice concentration variable");
 
  // check and re-normalize sublattice B site fractions
  Real sum = _a_u;
  for (std::size_t i = 0; i < _ncs; ++i)
    sum += _a_cs[i];
  if (sum <= 0.0)
    paramError("as", "The sum of the 'as' values and 'a' must be greater than zero");
  for (std::size_t i = 0; i < _ncs; ++i)
    _a_cs[i] /= sum;
  _a_u /= sum;
 
  // fetch coupled concentrations
  for (std::size_t i = 0; i < _ncs; ++i)
    _cs[i] = &coupledValue("cs", i);
}

Member Function Documentation

computeQpJacobian()

Real SLKKSSum::computeQpJacobian ( )

protectedvirtual

Definition at line 66 of file SLKKSSum.C.

{
  return _test[_i][_qp] * _phi[_j][_qp] * _a_u;
}

computeQpOffDiagJacobian()

Real SLKKSSum::computeQpOffDiagJacobian ( unsigned int  jvar )

protectedvirtual

Definition at line 72 of file SLKKSSum.C.

{
  auto csvar = mapJvarToCvar(jvar, _cs_map);
  if (csvar >= 0)
    return _test[_i][_qp] * _phi[_j][_qp] * _a_cs[csvar];
 
  return 0.0;
}

computeQpResidual()

Real SLKKSSum::computeQpResidual ( )

protectedvirtual

Definition at line 56 of file SLKKSSum.C.

{
  Real csum = _u[_qp] * _a_u;
  for (std::size_t i = 0; i < _ncs; ++i)
    csum += (*_cs[i])[_qp] * _a_cs[i];
 
  return _test[_i][_qp] * (csum - _target[_qp]);
}

validParams()

InputParameters SLKKSSum::validParams ( )

static

Definition at line 16 of file SLKKSSum.C.

{
  auto params = Kernel::validParams();
  params.addClassDescription(
      "Enforce the sum of sublattice concentrations to a given phase concentration.");
  params.addRequiredCoupledVar("cs", "other sublattice concentrations in the same phase");
  params.addRequiredParam<Real>("a", "Sublattice site fraction for the kernel variable");
  params.addRequiredParam<std::vector<Real>>("as", "Phase a sublattice site fractions");
  params.addRequiredCoupledVar("sum", "prescribed sum");
  return params;
}

Member Data Documentation

_a_cs

std::vector<Real> SLKKSSum::_a_cs

protected

Definition at line 37 of file SLKKSSum.h.

Referenced by computeQpOffDiagJacobian(), computeQpResidual(), and SLKKSSum().

_a_u

Real SLKKSSum::_a_u

protected

sublattice fraction for the sublattice B concentration represented by the kernel variable

Definition at line 42 of file SLKKSSum.h.

Referenced by computeQpJacobian(), computeQpResidual(), and SLKKSSum().

_cs

std::vector<const VariableValue *> SLKKSSum::_cs

protected

Definition at line 36 of file SLKKSSum.h.

Referenced by computeQpResidual(), and SLKKSSum().

_cs_map

const JvarMap& SLKKSSum::_cs_map

protected

Definition at line 38 of file SLKKSSum.h.

Referenced by computeQpOffDiagJacobian().

_ncs

unsigned int SLKKSSum::_ncs

protected

sublattice A variables

Definition at line 35 of file SLKKSSum.h.

Referenced by computeQpResidual(), and SLKKSSum().

_target

const VariableValue& SLKKSSum::_target

protected

AuxVariable to hold the target sum.

Definition at line 45 of file SLKKSSum.h.

Referenced by computeQpResidual().

---

The documentation for this class was generated from the following files:

• phase_field/include/kernels/SLKKSSum.h
• phase_field/src/kernels/SLKKSSum.C