src/turbulenceModels/compressible/RAS/LaunderSharmaKE/LaunderSharmaKE.C

   1 /*---------------------------------------------------------------------------*\
   2   =========                 |
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   5     \\  /    A nd           | Copyright (C) 1991-2009 OpenCFD Ltd.
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   7 -------------------------------------------------------------------------------
   8 License
   9     This file is part of OpenFOAM.
  10
  11     OpenFOAM is free software; you can redistribute it and/or modify it
  12     under the terms of the GNU General Public License as published by the
  13     Free Software Foundation; either version 2 of the License, or (at your
  14     option) any later version.
  15
  16     OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
  17     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  18     FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  19     for more details.
  20
  21     You should have received a copy of the GNU General Public License
  22     along with OpenFOAM; if not, write to the Free Software Foundation,
  23     Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  24
  25 \*---------------------------------------------------------------------------*/
  26
  27 #include "LaunderSharmaKE.H"
  28 #include "addToRunTimeSelectionTable.H"
  29
  30 #include "backwardsCompatibilityWallFunctions.H"
  31
  32 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
  33
  34 namespace Foam
  35 {
  36 namespace compressible
  37 {
  38 namespace RASModels
  39 {
  40
  41 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
  42
  43 defineTypeNameAndDebug(LaunderSharmaKE, 0);
  44 addToRunTimeSelectionTable(RASModel, LaunderSharmaKE, dictionary);
  45
  46 // * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * * //
  47
  48 tmp<volScalarField> LaunderSharmaKE::fMu() const
  49 {
  50     return exp(-3.4/sqr(scalar(1) + rho_*sqr(k_)/(mu()*epsilon_)/50.0));
  51 }
  52
  53
  54 tmp<volScalarField> LaunderSharmaKE::f2() const
  55 {
  56     return
  57         scalar(1)
  58       - 0.3*exp(-min(sqr(rho_*sqr(k_)/(mu()*epsilon_)), scalar(50.0)));
  59 }
  60
  61
  62 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
  63
  64 LaunderSharmaKE::LaunderSharmaKE
  65 (
  66     const volScalarField& rho,
  67     const volVectorField& U,
  68     const surfaceScalarField& phi,
  69     const basicThermo& thermophysicalModel
  70 )
  71 :
  72     RASModel(typeName, rho, U, phi, thermophysicalModel),
  73
  74     Cmu_
  75     (
  76         dimensioned<scalar>::lookupOrAddToDict
  77         (
  78             "Cmu",
  79             coeffDict_,
  80             0.09
  81         )
  82     ),
  83     C1_
  84     (
  85         dimensioned<scalar>::lookupOrAddToDict
  86         (
  87             "C1",
  88             coeffDict_,
  89             1.44
  90         )
  91     ),
  92     C2_
  93     (
  94         dimensioned<scalar>::lookupOrAddToDict
  95         (
  96             "C2",
  97             coeffDict_,
  98             1.92
  99         )
 100     ),
 101     C3_
 102     (
 103         dimensioned<scalar>::lookupOrAddToDict
 104         (
 105             "C3",
 106             coeffDict_,
 107             -0.33
 108         )
 109     ),
 110     sigmak_
 111     (
 112         dimensioned<scalar>::lookupOrAddToDict
 113         (
 114             "sigmak",
 115             coeffDict_,
 116             1.0
 117         )
 118     ),
 119     sigmaEps_
 120     (
 121         dimensioned<scalar>::lookupOrAddToDict
 122         (
 123             "sigmaEps",
 124             coeffDict_,
 125             1.3
 126         )
 127     ),
 128     Prt_
 129     (
 130         dimensioned<scalar>::lookupOrAddToDict
 131         (
 132             "Prt",
 133             coeffDict_,
 134             1.0
 135         )
 136     ),
 137
 138     k_
 139     (
 140         IOobject
 141         (
 142             "k",
 143             runTime_.timeName(),
 144             mesh_,
 145             IOobject::NO_READ,
 146             IOobject::AUTO_WRITE
 147         ),
 148         autoCreateK("k", mesh_)
 149     ),
 150
 151     epsilon_
 152     (
 153         IOobject
 154         (
 155             "epsilon",
 156             runTime_.timeName(),
 157             mesh_,
 158             IOobject::NO_READ,
 159             IOobject::AUTO_WRITE
 160         ),
 161         autoCreateEpsilon("epsilon", mesh_)
 162     ),
 163
 164     mut_
 165     (
 166         IOobject
 167         (
 168             "mut",
 169             runTime_.timeName(),
 170             mesh_,
 171             IOobject::NO_READ,
 172             IOobject::NO_WRITE
 173         ),
 174         autoCreateMut("mut", mesh_)
 175     ),
 176
 177     alphat_
 178     (
 179         IOobject
 180         (
 181             "alphat",
 182             runTime_.timeName(),
 183             mesh_,
 184             IOobject::NO_READ,
 185             IOobject::AUTO_WRITE
 186         ),
 187         autoCreateAlphat("alphat", mesh_)
 188     )
 189 {
 190     mut_ = rho_*Cmu_*fMu()*sqr(k_)/(epsilon_ + epsilonSmall_);
 191     mut_.correctBoundaryConditions();
 192
 193     alphat_ = mut_/Prt_;
 194     alphat_.correctBoundaryConditions();
 195
 196     printCoeffs();
 197 }
 198
 199
 200 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 201
 202 tmp<volSymmTensorField> LaunderSharmaKE::R() const
 203 {
 204     return tmp<volSymmTensorField>
 205     (
 206         new volSymmTensorField
 207         (
 208             IOobject
 209             (
 210                 "R",
 211                 runTime_.timeName(),
 212                 mesh_,
 213                 IOobject::NO_READ,
 214                 IOobject::NO_WRITE
 215             ),
 216             ((2.0/3.0)*I)*k_ - (mut_/rho_)*dev(twoSymm(fvc::grad(U_))),
 217             k_.boundaryField().types()
 218         )
 219     );
 220 }
 221
 222
 223 tmp<volSymmTensorField> LaunderSharmaKE::devRhoReff() const
 224 {
 225     return tmp<volSymmTensorField>
 226     (
 227         new volSymmTensorField
 228         (
 229             IOobject
 230             (
 231                 "devRhoReff",
 232                 runTime_.timeName(),
 233                 mesh_,
 234                 IOobject::NO_READ,
 235                 IOobject::NO_WRITE
 236             ),
 237            -muEff()*dev(twoSymm(fvc::grad(U_)))
 238         )
 239     );
 240 }
 241
 242
 243 tmp<fvVectorMatrix> LaunderSharmaKE::divDevRhoReff(volVectorField& U) const
 244 {
 245     return
 246     (
 247       - fvm::laplacian(muEff(), U) - fvc::div(muEff()*dev2(fvc::grad(U)().T()))
 248     );
 249 }
 250
 251
 252 bool LaunderSharmaKE::read()
 253 {
 254     if (RASModel::read())
 255     {
 256         Cmu_.readIfPresent(coeffDict());
 257         C1_.readIfPresent(coeffDict());
 258         C2_.readIfPresent(coeffDict());
 259         C3_.readIfPresent(coeffDict());
 260         sigmak_.readIfPresent(coeffDict());
 261         sigmaEps_.readIfPresent(coeffDict());
 262         Prt_.readIfPresent(coeffDict());
 263
 264         return true;
 265     }
 266     else
 267     {
 268         return false;
 269     }
 270 }
 271
 272
 273 void LaunderSharmaKE::correct()
 274 {
 275     if (!turbulence_)
 276     {
 277         // Re-calculate viscosity
 278         mut_ = rho_*Cmu_*fMu()*sqr(k_)/(epsilon_ + epsilonSmall_);
 279         mut_.correctBoundaryConditions();
 280
 281         // Re-calculate thermal diffusivity
 282         alphat_ = mut_/Prt_;
 283         alphat_.correctBoundaryConditions();
 284
 285         return;
 286     }
 287
 288     RASModel::correct();
 289
 290     // Calculate parameters and coefficients for Launder-Sharma low-Reynolds
 291     // number model
 292
 293     volScalarField E = 2.0*mu()*mut_*fvc::magSqrGradGrad(U_)/rho_;
 294     volScalarField D = 2.0*mu()*magSqr(fvc::grad(sqrt(k_)))/rho_;
 295
 296     volScalarField divU = fvc::div(phi_/fvc::interpolate(rho_));
 297
 298     if (mesh_.moving())
 299     {
 300         divU += fvc::div(mesh_.phi());
 301     }
 302
 303     tmp<volTensorField> tgradU = fvc::grad(U_);
 304     volScalarField G("RASModel::G", mut_*(tgradU() && dev(twoSymm(tgradU()))));
 305     tgradU.clear();
 306
 307     // Update espsilon and G at the wall
 308     epsilon_.boundaryField().updateCoeffs();
 309
 310     // Dissipation equation
 311
 312     tmp<fvScalarMatrix> epsEqn
 313     (
 314         fvm::ddt(rho_, epsilon_)
 315       + fvm::div(phi_, epsilon_)
 316       - fvm::laplacian(DepsilonEff(), epsilon_)
 317      ==
 318         C1_*G*epsilon_/k_ + fvm::SuSp((C3_ - 2.0/3.0*C1_)*rho_*divU, epsilon_)
 319       - fvm::Sp(C2_*f2()*rho_*epsilon_/k_, epsilon_)
 320     //+ 0.75*1.5*flameKproduction*epsilon_/k_
 321       + E
 322     );
 323
 324     epsEqn().relax();
 325
 326     epsEqn().boundaryManipulate(epsilon_.boundaryField());
 327
 328     solve(epsEqn);
 329     bound(epsilon_, epsilon0_);
 330
 331
 332     // Turbulent kinetic energy equation
 333
 334     tmp<fvScalarMatrix> kEqn
 335     (
 336         fvm::ddt(rho_, k_)
 337       + fvm::div(phi_, k_)
 338       - fvm::laplacian(DkEff(), k_)
 339      ==
 340         G - fvm::SuSp(2.0/3.0*rho_*divU, k_)
 341       - fvm::Sp(rho_*(epsilon_ + D)/k_, k_)
 342     //+ flameKproduction
 343     );
 344
 345     kEqn().relax();
 346     solve(kEqn);
 347     bound(k_, k0_);
 348
 349
 350     // Re-calculate viscosity
 351     mut_ = Cmu_*fMu()*rho_*sqr(k_)/(epsilon_ + epsilonSmall_);
 352     mut_.correctBoundaryConditions();
 353
 354     // Re-calculate thermal diffusivity
 355     alphat_ = mut_/Prt_;
 356     alphat_.correctBoundaryConditions();
 357 }
 358
 359
 360 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 361
 362 } // End namespace RASModels
 363 } // End namespace compressible
 364 } // End namespace Foam
 365
 366 // ************************************************************************* //