INSMomentumNoBCBCTractionForm.C
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1 /****************************************************************/
2 /* MOOSE - Multiphysics Object Oriented Simulation Environment */
3 /* */
4 /* All contents are licensed under LGPL V2.1 */
5 /* See LICENSE for full restrictions */
6 /****************************************************************/
7
9 #include "MooseMesh.h"
10
11 template <>
12 InputParameters
14 {
15  InputParameters params = validParams<INSMomentumNoBCBCBase>();
16
17  params.addClassDescription("This class implements the 'No BC' boundary condition based on the "
18  "'traction' form of the viscous stress tensor.");
19  return params;
20 }
21
23  : INSMomentumNoBCBCBase(parameters)
24 {
25 }
26
27 Real
29 {
30  // Compute n . sigma . v, where n is unit normal and v is the test function.
31  RealTensorValue sigma;
32
33  // First row
34  sigma(0, 0) = 2. * _mu[_qp] * _grad_u_vel[_qp](0);
37
38  // Second row
40  sigma(1, 1) = 2. * _mu[_qp] * _grad_v_vel[_qp](1);
42
43  // Third row
46  sigma(2, 2) = 2. * _mu[_qp] * _grad_w_vel[_qp](2);
47
48  // If the pressure term is integrated by parts, it is part of the
49  // no-BC-BC, otherwise, it is not.
51  {
52  sigma(0, 0) -= _p[_qp];
53  sigma(1, 1) -= _p[_qp];
54  sigma(2, 2) -= _p[_qp];
55  }
56
57  // Set up test function
58  RealVectorValue test;
59  test(_component) = _test[_i][_qp];
60
61  return -_normals[_qp] * (sigma * test);
62 }
63
64 Real
66 {
67  // The extra contribution comes from the "2" on the diagonal of the viscous stress tensor
68  return -_mu[_qp] * (_grad_phi[_j][_qp] * _normals[_qp] +
70  _test[_i][_qp];
71 }
72
73 Real
75 {
76  if (jvar == _u_vel_var_number)
77  return -_mu[_qp] * _grad_phi[_j][_qp](_component) * _normals[_qp](0) * _test[_i][_qp];
78
79  else if (jvar == _v_vel_var_number)
80  return -_mu[_qp] * _grad_phi[_j][_qp](_component) * _normals[_qp](1) * _test[_i][_qp];
81
82  else if (jvar == _w_vel_var_number)
83  return -_mu[_qp] * _grad_phi[_j][_qp](_component) * _normals[_qp](2) * _test[_i][_qp];
84
85  else if (jvar == _p_var_number)
86  {
88  return _phi[_j][_qp] * _normals[_qp](_component) * _test[_i][_qp];
89  else
90  return 0.;
91  }
92
93  else
94  return 0.;
95 }