DistributedForce Class Reference

The DistributedForce kernel computes the body force due to the acceleration of mass in an element. More...

#include <DistributedForce.h>

Inheritance diagram for DistributedForce:

Public Member Functions
	DistributedForce (const InputParameters &parameters)

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

Protected Attributes
unsigned int	_component
Real	_acceleration
unsigned int	_rho_var_number
const VariableValue &	_rho

Detailed Description

The DistributedForce kernel computes the body force due to the acceleration of mass in an element.

Following F=ma, the density must be integrated over the volume to yield the mass of the volume. In this kernel, the acceleration is assumed to be a constant defined by up to three dimensional components as input. The density must be obtained from the conservation of mass equation as a coupled variable. Typical use of this kernel is the gravitational force acting upon the fluid.

Definition at line 27 of file DistributedForce.h.

Constructor & Destructor Documentation

DistributedForce()

DistributedForce::DistributedForce

(

const InputParameters &

parameters

)

Definition at line 33 of file DistributedForce.C.

  : Kernel(parameters),
    _component(getParam<unsigned int>("component")),
    _acceleration(getParam<RealVectorValue>("acceleration")(_component)),
    _rho_var_number(coupled("rho")),
    _rho(coupledValue("rho"))
{
}

Member Function Documentation

computeQpJacobian()

Real DistributedForce::computeQpJacobian ( )

protectedvirtual

Definition at line 50 of file DistributedForce.C.

{
  return 0.;
}

computeQpOffDiagJacobian()

Real DistributedForce::computeQpOffDiagJacobian ( unsigned int  jvar )

protectedvirtual

Definition at line 56 of file DistributedForce.C.

{
  if (jvar == _rho_var_number)
    return -_phi[_j][_qp] * _acceleration * _test[_i][_qp];
 
  return 0;
}

computeQpResidual()

Real DistributedForce::computeQpResidual ( )

protectedvirtual

Definition at line 43 of file DistributedForce.C.

{
  // -rho * g * phi
  return -_rho[_qp] * _acceleration * _test[_i][_qp];
}

Member Data Documentation

_acceleration

Real DistributedForce::_acceleration

protected

Definition at line 38 of file DistributedForce.h.

Referenced by computeQpOffDiagJacobian(), and computeQpResidual().

_component

unsigned int DistributedForce::_component

protected

Definition at line 37 of file DistributedForce.h.

_rho

const VariableValue& DistributedForce::_rho

protected

Definition at line 40 of file DistributedForce.h.

Referenced by computeQpResidual().

_rho_var_number

unsigned int DistributedForce::_rho_var_number

protected

Definition at line 39 of file DistributedForce.h.

Referenced by computeQpOffDiagJacobian().

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

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