FreeFOAM The Cross-Platform CFD Toolkit
LRRDiffStress.C
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25 
26 #include "LRRDiffStress.H"
28 
29 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
30 
31 namespace Foam
32 {
33 namespace incompressible
34 {
35 namespace LESModels
36 {
37 
38 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
39 
40 defineTypeNameAndDebug(LRRDiffStress, 0);
41 addToRunTimeSelectionTable(LESModel, LRRDiffStress, dictionary);
42 
43 // * * * * * * * * * * * * * Private Member Functions * * * * * * * * * * * //
44 
45 void LRRDiffStress::updateSubGridScaleFields(const volScalarField& K)
46 {
47  nuSgs_ = ck_*sqrt(K)*delta();
49 }
50 
51 
52 // * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * //
53 
54 LRRDiffStress::LRRDiffStress
55 (
56  const volVectorField& U,
57  const surfaceScalarField& phi,
58  transportModel& transport
59 )
60 :
61  LESModel(typeName, U, phi, transport),
62  GenSGSStress(U, phi, transport),
63 
64  ck_
65  (
67  (
68  "ck",
69  coeffDict_,
70  0.09
71  )
72  ),
73  c1_
74  (
76  (
77  "c1",
78  coeffDict_,
79  1.8
80  )
81  ),
82  c2_
83  (
85  (
86  "c2",
87  coeffDict_,
88  0.6
89  )
90  )
91 {
92  updateSubGridScaleFields(0.5*tr(B_));
93 
94  printCoeffs();
95 }
96 
97 
98 // * * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * //
99 
101 {
102  const volTensorField& gradU = tgradU();
103 
104  GenSGSStress::correct(gradU);
105 
106  volSymmTensorField D = symm(gradU);
107 
108  volSymmTensorField P = -twoSymm(B_ & gradU);
109 
110  volScalarField K = 0.5*tr(B_);
111  volScalarField Epsilon = 2*nuEff()*magSqr(D);
112 
113  fvSymmTensorMatrix BEqn
114  (
115  fvm::ddt(B_)
116  + fvm::div(phi(), B_)
117  - fvm::laplacian(DBEff(), B_)
118  + fvm::Sp(c1_*Epsilon/K, B_)
119  ==
120  P
121  - (0.667*(1.0 - c1_)*I)*Epsilon
122  - c2_*(P - 0.333*I*tr(P))
123  - (0.667 - 2*c1_)*I*pow(K, 1.5)/delta()
124  );
125 
126  BEqn.relax();
127  BEqn.solve();
128 
129  // Bounding the component kinetic energies
130 
131  forAll(B_, celli)
132  {
133  B_[celli].component(symmTensor::XX) =
134  max(B_[celli].component(symmTensor::XX), k0().value());
135  B_[celli].component(symmTensor::YY) =
136  max(B_[celli].component(symmTensor::YY), k0().value());
137  B_[celli].component(symmTensor::ZZ) =
138  max(B_[celli].component(symmTensor::ZZ), k0().value());
139  }
140 
141  K = 0.5*tr(B_);
142  bound(K, k0());
143 
144  updateSubGridScaleFields(K);
145 }
146 
147 
149 {
150  if (GenSGSStress::read())
151  {
152  ck_.readIfPresent(coeffDict());
153  c1_.readIfPresent(coeffDict());
154  c2_.readIfPresent(coeffDict());
155 
156  return true;
157  }
158  else
159  {
160  return false;
161  }
162 }
163 
164 
165 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
166 
167 } // End namespace LESModels
168 } // End namespace incompressible
169 } // End namespace Foam
170 
171 // ************************ vim: set sw=4 sts=4 et: ************************ //