CHMath Class Reference

Cahn-Hilliard Kernel implementing the free energy f = 1/4(1-c^2)^2, such that grad df/dc = (3 c^2 -1) grad_c. More...

#include <CHMath.h>

Inheritance diagram for CHMath:

Public Member Functions
	CHMath (const InputParameters &parameters)
virtual void	initialSetup ()

Static Public Member Functions
static InputParameters	validParams ()

Protected Types
enum	PFFunctionType

Protected Member Functions
virtual RealGradient	computeGradDFDCons (PFFunctionType type)
virtual RealGradient	precomputeQpResidual ()
virtual RealGradient	precomputeQpJacobian ()
virtual Real	computeQpOffDiagJacobian (unsigned int jvar)
virtual RealGradient	computeGradDFDCons (PFFunctionType type)=0

Protected Attributes
const MaterialProperty< Real > &	_M
	Mobility. More...
const MaterialProperty< Real > &	_dMdc
	Mobility derivative w.r.t. concentration. More...
std::vector< const MaterialProperty< Real > * >	_dMdarg
	Mobility derivative w.r.t coupled variables. More...

Detailed Description

Cahn-Hilliard Kernel implementing the free energy f = 1/4(1-c^2)^2, such that grad df/dc = (3 c^2 -1) grad_c.

Most of the Cahn-Hilliard equation is implemented in CHBulk and CHInterface. This kernel inherents from CHBulk and implements a simple polynomial double well to model spinodal decomposition. See M.R. Tonks et al. / Computational Materials Science 51 (2012) 20-29, Eqs 11 and 12.

Definition at line 27 of file CHMath.h.

Member Enumeration Documentation

PFFunctionType

enum CHBulk::PFFunctionType

protectedinherited

Definition at line 38 of file CHBulk.h.

  {
    Jacobian,
    Residual
  };

Constructor & Destructor Documentation

CHMath()

CHMath::CHMath

(

const InputParameters &

parameters

)

Definition at line 24 of file CHMath.C.

: CHBulk<Real>(parameters) {}

Member Function Documentation

computeGradDFDCons() [1/2]

RealGradient CHMath::computeGradDFDCons ( PFFunctionType  type )

protectedvirtual

Definition at line 27 of file CHMath.C.

{
  switch (type)
  {
    case Residual:
      return 3 * _u[_qp] * _u[_qp] * _grad_u[_qp] - _grad_u[_qp]; // return Residual value
 
    case Jacobian:
      return 6 * _u[_qp] * _phi[_j][_qp] * _grad_u[_qp] +
             3 * _u[_qp] * _u[_qp] * _grad_phi[_j][_qp] -
             _grad_phi[_j][_qp]; // return Jacobian value
  }
 
  mooseError("Invalid type passed in");
}

computeGradDFDCons() [2/2]

virtual RealGradient CHBulk< Real >::computeGradDFDCons ( PFFunctionType  type )

protectedpure virtualinherited

Implemented in CahnHilliardBase< Real >.

computeQpOffDiagJacobian()

Real CHBulk< Real >::computeQpOffDiagJacobian ( unsigned int  jvar )

protectedvirtualinherited

Reimplemented in KKSCHBulk, and CahnHilliardBase< Real >.

Definition at line 110 of file CHBulk.h.

{
  // get the coupled variable jvar is referring to
  const unsigned int cvar = mapJvarToCvar(jvar);
 
  return (*_dMdarg[cvar])[_qp] * _phi[_j][_qp] * computeGradDFDCons(Residual) * _grad_test[_i][_qp];
}

initialSetup()

void CHBulk< Real >::initialSetup ( )

virtualinherited

Reimplemented in CahnHilliardBase< Real >.

Definition at line 86 of file CHBulk.h.

{
  validateNonlinearCoupling<Real>("mob_name");
}

precomputeQpJacobian()

RealGradient CHBulk< Real >::precomputeQpJacobian ( )

protectedvirtualinherited

Definition at line 100 of file CHBulk.h.

{
  RealGradient grad_value = _M[_qp] * computeGradDFDCons(Jacobian) +
                            _dMdc[_qp] * _phi[_j][_qp] * computeGradDFDCons(Residual);
 
  return grad_value;
}

precomputeQpResidual()

RealGradient CHBulk< Real >::precomputeQpResidual ( )

protectedvirtualinherited

Definition at line 93 of file CHBulk.h.

{
  return _M[_qp] * computeGradDFDCons(Residual);
}

validParams()

InputParameters CHBulk< Real >::validParams ( )

staticinherited

Definition at line 75 of file CHBulk.h.

{
  InputParameters params = ::validParams<KernelGrad>();
  params.addClassDescription("Cahn-Hilliard base Kernel");
  params.addParam<MaterialPropertyName>("mob_name", "M", "The mobility used with the kernel");
  params.addCoupledVar("args", "Vector of arguments of the mobility");
  return params;
}

Member Data Documentation

_dMdarg

std::vector<const MaterialProperty<Real > *> CHBulk< Real >::_dMdarg

protectedinherited

Mobility derivative w.r.t coupled variables.

Definition at line 53 of file CHBulk.h.

_dMdc

const MaterialProperty<Real >& CHBulk< Real >::_dMdc

protectedinherited

Mobility derivative w.r.t. concentration.

Definition at line 50 of file CHBulk.h.

_M

const MaterialProperty<Real >& CHBulk< Real >::_M

protectedinherited

Mobility.

Definition at line 47 of file CHBulk.h.

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

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