INSSplitMomentum Class Reference

This class computes the "split" momentum equation residual. More...

#include <INSSplitMomentum.h>

Inheritance diagram for INSSplitMomentum:

Public Member Functions
	INSSplitMomentum (const InputParameters &parameters)
virtual	~INSSplitMomentum ()

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

Protected Attributes
const VariableValue &	_u_vel
const VariableValue &	_v_vel
const VariableValue &	_w_vel
const VariableValue &	_a1
const VariableValue &	_a2
const VariableValue &	_a3
const VariableGradient &	_grad_u_vel
const VariableGradient &	_grad_v_vel
const VariableGradient &	_grad_w_vel
unsigned	_u_vel_var_number
unsigned	_v_vel_var_number
unsigned	_w_vel_var_number
unsigned	_a1_var_number
unsigned	_a2_var_number
unsigned	_a3_var_number
RealVectorValue	_gravity
unsigned	_component
const MaterialProperty< Real > &	_mu
const MaterialProperty< Real > &	_rho

Detailed Description

This class computes the "split" momentum equation residual.

In the split method, this is a time-independent vector equation for "a", an intermediate "acceleration" vector. The pressure is not coupled directly to momentum in the split method. Note: this equation is divided through by the density, so "nu" appears rather than "mu", for instance.

Do not use, USE INSChorinPredictor and related classes instead.

Definition at line 31 of file INSSplitMomentum.h.

Constructor & Destructor Documentation

INSSplitMomentum()

INSSplitMomentum::INSSplitMomentum

(

const InputParameters &

parameters

)

Definition at line 44 of file INSSplitMomentum.C.

  : Kernel(parameters),

    // Coupled variables
    _u_vel(coupledValue("u")),
    _v_vel(_mesh.dimension() >= 2 ? coupledValue("v") : _zero),
    _w_vel(_mesh.dimension() == 3 ? coupledValue("w") : _zero),

    _a1(coupledValue("a1")),
    _a2(_mesh.dimension() >= 2 ? coupledValue("a2") : _zero),
    _a3(_mesh.dimension() == 3 ? coupledValue("a3") : _zero),

    // Gradients
    _grad_u_vel(coupledGradient("u")),
    _grad_v_vel(_mesh.dimension() >= 2 ? coupledGradient("v") : _grad_zero),
    _grad_w_vel(_mesh.dimension() == 3 ? coupledGradient("w") : _grad_zero),

    // Variable numberings
    _u_vel_var_number(coupled("u")),
    _v_vel_var_number(_mesh.dimension() >= 2 ? coupled("v") : libMesh::invalid_uint),
    _w_vel_var_number(_mesh.dimension() == 3 ? coupled("w") : libMesh::invalid_uint),

    _a1_var_number(coupled("a1")),
    _a2_var_number(_mesh.dimension() >= 2 ? coupled("a2") : libMesh::invalid_uint),
    _a3_var_number(_mesh.dimension() == 3 ? coupled("a3") : libMesh::invalid_uint),

    // Required parameters
    _gravity(getParam<RealVectorValue>("gravity")),
    _component(getParam<unsigned>("component")),

    // Material properties
    _mu(getMaterialProperty<Real>("mu_name")),
    _rho(getMaterialProperty<Real>("rho_name"))
{
}

~INSSplitMomentum()

virtual INSSplitMomentum::~INSSplitMomentum ( )

inlinevirtual

Definition at line 36 of file INSSplitMomentum.h.

{}

Member Function Documentation

computeQpJacobian()

Real INSSplitMomentum::computeQpJacobian ( )

protectedvirtual

Definition at line 134 of file INSSplitMomentum.C.

{
  // The on-diagonal Jacobian contribution (derivative of a.test wrt a)
  // is just the mass matrix entry.
  return _phi[_j][_qp] * _test[_i][_qp];
}

computeQpOffDiagJacobian()

Real INSSplitMomentum::computeQpOffDiagJacobian ( unsigned  jvar )

protectedvirtual

Definition at line 142 of file INSSplitMomentum.C.

{
  if ((jvar == _u_vel_var_number) || (jvar == _v_vel_var_number) || (jvar == _w_vel_var_number))
  {
    // Derivative of viscous stress tensor
    RealTensorValue dtau;

    // Initialize to invalid value, then determine correct value.
    unsigned vel_index = 99;

    // Set index and build dtau for that index
    if (jvar == _u_vel_var_number)
    {
      vel_index = 0;
      dtau(0, 0) = 2. * _grad_phi[_j][_qp](0);
      dtau(0, 1) = _grad_phi[_j][_qp](1);
      dtau(0, 2) = _grad_phi[_j][_qp](2);
      dtau(1, 0) = _grad_phi[_j][_qp](1);
      dtau(2, 0) = _grad_phi[_j][_qp](2);
    }
    else if (jvar == _v_vel_var_number)
    {
      vel_index = 1;
      /*                                 */ dtau(0, 1) = _grad_phi[_j][_qp](0);
      dtau(1, 0) = _grad_phi[_j][_qp](0);
      dtau(1, 1) = 2. * _grad_phi[_j][_qp](1);
      dtau(1, 2) = _grad_phi[_j][_qp](2);
      /*                                 */ dtau(2, 1) = _grad_phi[_j][_qp](2);
    }
    else if (jvar == _w_vel_var_number)
    {
      vel_index = 2;
      /*                                                                     */ dtau(0, 2) =
          _grad_phi[_j][_qp](0);
      /*                                                                     */ dtau(1, 2) =
          _grad_phi[_j][_qp](1);
      dtau(2, 0) = _grad_phi[_j][_qp](0);
      dtau(2, 1) = _grad_phi[_j][_qp](1);
      dtau(2, 2) = 2. * _grad_phi[_j][_qp](2);
    }

    // Vector object for test function
    RealVectorValue test;
    test(_component) = _test[_i][_qp];

    // Vector object for U
    RealVectorValue U(_u_vel[_qp], _v_vel[_qp], _w_vel[_qp]);

    // Tensor object for test function gradient
    RealTensorValue grad_test;
    for (unsigned k = 0; k < 3; ++k)
      grad_test(_component, k) = _grad_test[_i][_qp](k);

    // Compute the convective part
    RealVectorValue convective_jac = _phi[_j][_qp] * RealVectorValue(_grad_u_vel[_qp](vel_index),
                                                                     _grad_v_vel[_qp](vel_index),
                                                                     _grad_w_vel[_qp](vel_index));

    // Extra contribution in vel_index component
    convective_jac(vel_index) += U * _grad_phi[_j][_qp];
    Real convective_part = convective_jac * test;

    // Compute the viscous part
    Real viscous_part = (_mu[_qp] / _rho[_qp]) * dtau.contract(grad_test);

    // Return the result
    return convective_part + viscous_part;
  }

  else
    return 0;
}

computeQpResidual()

Real INSSplitMomentum::computeQpResidual ( )

protectedvirtual

Definition at line 81 of file INSSplitMomentum.C.

{
  // Vector object for a
  RealVectorValue a(_a1[_qp], _a2[_qp], _a3[_qp]);

  // Vector object for test function
  RealVectorValue test;
  test(_component) = _test[_i][_qp];

  // Tensor object for "grad U" = d(u_i)/d(x_j)
  RealTensorValue grad_U(_grad_u_vel[_qp], _grad_v_vel[_qp], _grad_w_vel[_qp]);

  // Vector object for U
  RealVectorValue U(_u_vel[_qp], _v_vel[_qp], _w_vel[_qp]);

  // Viscous stress tensor object
  RealTensorValue tau(
      // Row 1
      2. * _grad_u_vel[_qp](0),
      _grad_u_vel[_qp](1) + _grad_v_vel[_qp](0),
      _grad_u_vel[_qp](2) + _grad_w_vel[_qp](0),
      // Row 2
      _grad_v_vel[_qp](0) + _grad_u_vel[_qp](1),
      2. * _grad_v_vel[_qp](1),
      _grad_v_vel[_qp](2) + _grad_w_vel[_qp](1),
      // Row 3
      _grad_w_vel[_qp](0) + _grad_u_vel[_qp](2),
      _grad_w_vel[_qp](1) + _grad_v_vel[_qp](2),
      2. * _grad_w_vel[_qp](2));

  // Tensor object for test function gradient
  RealTensorValue grad_test;
  for (unsigned k = 0; k < 3; ++k)
    grad_test(_component, k) = _grad_test[_i][_qp](k);

  //
  // Compute the different pieces...
  //

  // "Symmetric" part, a.test
  Real symmetric_part = a(_component) * _test[_i][_qp];

  // The convection part, (u.grad) * u_component * test_scalar.  Which can also be
  // written as (grad_U * U) * test_vec
  Real convective_part = (grad_U * U) * test;

  // The viscous part, tau : grad(v)
  Real viscous_part = (_mu[_qp] / _rho[_qp]) * tau.contract(grad_test);

  return symmetric_part + convective_part + viscous_part;
}

Member Data Documentation

_a1

const VariableValue& INSSplitMomentum::_a1

protected

Definition at line 49 of file INSSplitMomentum.h.

Referenced by computeQpResidual().

_a1_var_number

unsigned INSSplitMomentum::_a1_var_number

protected

Definition at line 63 of file INSSplitMomentum.h.

_a2

const VariableValue& INSSplitMomentum::_a2

protected

Definition at line 50 of file INSSplitMomentum.h.

Referenced by computeQpResidual().

_a2_var_number

unsigned INSSplitMomentum::_a2_var_number

protected

Definition at line 64 of file INSSplitMomentum.h.

_a3

const VariableValue& INSSplitMomentum::_a3

protected

Definition at line 51 of file INSSplitMomentum.h.

Referenced by computeQpResidual().

_a3_var_number

unsigned INSSplitMomentum::_a3_var_number

protected

Definition at line 65 of file INSSplitMomentum.h.

_component

unsigned INSSplitMomentum::_component

protected

Definition at line 69 of file INSSplitMomentum.h.

Referenced by computeQpOffDiagJacobian(), and computeQpResidual().

_grad_u_vel

const VariableGradient& INSSplitMomentum::_grad_u_vel

protected

Definition at line 54 of file INSSplitMomentum.h.

Referenced by computeQpOffDiagJacobian(), and computeQpResidual().

_grad_v_vel

const VariableGradient& INSSplitMomentum::_grad_v_vel

protected

Definition at line 55 of file INSSplitMomentum.h.

Referenced by computeQpOffDiagJacobian(), and computeQpResidual().

_grad_w_vel

const VariableGradient& INSSplitMomentum::_grad_w_vel

protected

Definition at line 56 of file INSSplitMomentum.h.

Referenced by computeQpOffDiagJacobian(), and computeQpResidual().

_gravity

RealVectorValue INSSplitMomentum::_gravity

protected

Definition at line 68 of file INSSplitMomentum.h.

_mu

const MaterialProperty<Real>& INSSplitMomentum::_mu

protected

Definition at line 72 of file INSSplitMomentum.h.

Referenced by computeQpOffDiagJacobian(), and computeQpResidual().

_rho

const MaterialProperty<Real>& INSSplitMomentum::_rho

protected

Definition at line 73 of file INSSplitMomentum.h.

Referenced by computeQpOffDiagJacobian(), and computeQpResidual().

_u_vel

const VariableValue& INSSplitMomentum::_u_vel

protected

Definition at line 44 of file INSSplitMomentum.h.

Referenced by computeQpOffDiagJacobian(), and computeQpResidual().

_u_vel_var_number

unsigned INSSplitMomentum::_u_vel_var_number

protected

Definition at line 59 of file INSSplitMomentum.h.

Referenced by computeQpOffDiagJacobian().

_v_vel

const VariableValue& INSSplitMomentum::_v_vel

protected

Definition at line 45 of file INSSplitMomentum.h.

Referenced by computeQpOffDiagJacobian(), and computeQpResidual().

_v_vel_var_number

unsigned INSSplitMomentum::_v_vel_var_number

protected

Definition at line 60 of file INSSplitMomentum.h.

Referenced by computeQpOffDiagJacobian().

_w_vel

const VariableValue& INSSplitMomentum::_w_vel

protected

Definition at line 46 of file INSSplitMomentum.h.

Referenced by computeQpOffDiagJacobian(), and computeQpResidual().

_w_vel_var_number

unsigned INSSplitMomentum::_w_vel_var_number

protected

Definition at line 61 of file INSSplitMomentum.h.

Referenced by computeQpOffDiagJacobian().

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

• navier_stokes/include/kernels/INSSplitMomentum.h
• navier_stokes/src/kernels/INSSplitMomentum.C