src/turbulenceModels/compressible/LES/SpalartAllmaras/SpalartAllmaras.C

   1 /*---------------------------------------------------------------------------*\
   2   =========                 |
   3   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   4    \\    /   O peration     |
   5     \\  /    A nd           | Copyright (C) 2011 OpenFOAM Foundation
   6      \\/     M anipulation  |
   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
  13     the Free Software Foundation, either version 3 of the License, or
  14     (at your 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, see <http://www.gnu.org/licenses/>.
  23
  24 \*---------------------------------------------------------------------------*/
  25
  26 #include "SpalartAllmaras.H"
  27 #include "addToRunTimeSelectionTable.H"
  28 #include "wallDist.H"
  29
  30 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
  31
  32 namespace Foam
  33 {
  34 namespace compressible
  35 {
  36 namespace LESModels
  37 {
  38
  39 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
  40
  41 defineTypeNameAndDebug(SpalartAllmaras, 0);
  42 addToRunTimeSelectionTable(LESModel, SpalartAllmaras, dictionary);
  43
  44
  45 // * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * * //
  46
  47 void SpalartAllmaras::updateSubGridScaleFields()
  48 {
  49     muSgs_.internalField() = rho()*fv1()*nuTilda_.internalField();
  50     muSgs_.correctBoundaryConditions();
  51
  52     alphaSgs_ = muSgs_/Prt_;
  53     alphaSgs_.correctBoundaryConditions();
  54 }
  55
  56
  57 tmp<volScalarField> SpalartAllmaras::fv1() const
  58 {
  59     volScalarField chi3(pow3(rho()*nuTilda_/mu()));
  60     return chi3/(chi3 + pow3(Cv1_));
  61 }
  62
  63
  64 tmp<volScalarField> SpalartAllmaras::fv2() const
  65 {
  66     return 1.0/pow3(scalar(1) + rho()*nuTilda_/(mu()*Cv2_));
  67 }
  68
  69
  70 tmp<volScalarField> SpalartAllmaras::fv3() const
  71 {
  72     volScalarField chi(rho()*nuTilda_/mu());
  73     volScalarField chiByCv2((1/Cv2_)*chi);
  74
  75     return
  76         (scalar(1) + chi*fv1())
  77        *(1/Cv2_)
  78        *(3*(scalar(1) + chiByCv2) + sqr(chiByCv2))
  79        /pow3(scalar(1) + chiByCv2);
  80 }
  81
  82
  83 tmp<volScalarField> SpalartAllmaras::fw(const volScalarField& Stilda) const
  84 {
  85     volScalarField r
  86     (
  87         min
  88         (
  89             nuTilda_
  90            /(
  91                max
  92                (
  93                    Stilda,
  94                    dimensionedScalar("SMALL", Stilda.dimensions(), SMALL)
  95                )
  96               *sqr(kappa_*dTilda_)
  97             ),
  98             scalar(10.0)
  99         )
 100     );
 101     r.boundaryField() == 0.0;
 102
 103     volScalarField g(r + Cw2_*(pow6(r) - r));
 104
 105     return g*pow((1.0 + pow6(Cw3_))/(pow6(g) + pow6(Cw3_)), 1.0/6.0);
 106 }
 107
 108
 109 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 110
 111 SpalartAllmaras::SpalartAllmaras
 112 (
 113     const volScalarField& rho,
 114     const volVectorField& U,
 115     const surfaceScalarField& phi,
 116     const basicThermo& thermoPhysicalModel,
 117     const word& turbulenceModelName,
 118     const word& modelName
 119 )
 120 :
 121     LESModel(modelName, rho, U, phi, thermoPhysicalModel, turbulenceModelName),
 122
 123     sigmaNut_
 124     (
 125         dimensioned<scalar>::lookupOrAddToDict
 126         (
 127             "sigmaNut",
 128             coeffDict_,
 129             0.66666
 130         )
 131     ),
 132     Prt_
 133     (
 134         dimensioned<scalar>::lookupOrAddToDict
 135         (
 136             "Prt",
 137             coeffDict_,
 138             1.0
 139         )
 140     ),
 141
 142     Cb1_
 143     (
 144         dimensioned<scalar>::lookupOrAddToDict
 145         (
 146             "Cb1",
 147             coeffDict_,
 148             0.1355
 149         )
 150     ),
 151     Cb2_
 152     (
 153         dimensioned<scalar>::lookupOrAddToDict
 154         (
 155             "Cb2",
 156             coeffDict_,
 157             0.622
 158         )
 159     ),
 160     Cv1_
 161     (
 162         dimensioned<scalar>::lookupOrAddToDict
 163         (
 164             "Cv1",
 165             coeffDict_,
 166             7.1
 167         )
 168     ),
 169     Cv2_
 170     (
 171         dimensioned<scalar>::lookupOrAddToDict
 172         (
 173             "Cv2",
 174             coeffDict_,
 175             5.0
 176         )
 177     ),
 178     CDES_
 179     (
 180         dimensioned<scalar>::lookupOrAddToDict
 181         (
 182             "CDES",
 183             coeffDict_,
 184             0.65
 185         )
 186     ),
 187     ck_
 188     (
 189         dimensioned<scalar>::lookupOrAddToDict
 190         (
 191             "ck",
 192             coeffDict_,
 193             0.07
 194         )
 195     ),
 196     kappa_
 197     (
 198         dimensioned<scalar>::lookupOrAddToDict
 199         (
 200             "kappa",
 201             *this,
 202             0.41
 203         )
 204     ),
 205     Cw1_(Cb1_/sqr(kappa_) + (1.0 + Cb2_)/sigmaNut_),
 206     Cw2_
 207     (
 208         dimensioned<scalar>::lookupOrAddToDict
 209         (
 210             "Cw2",
 211             coeffDict_,
 212             0.3
 213         )
 214     ),
 215     Cw3_
 216     (
 217         dimensioned<scalar>::lookupOrAddToDict
 218         (
 219             "Cw3",
 220             coeffDict_,
 221             2.0
 222         )
 223     ),
 224
 225     nuTilda_
 226     (
 227         IOobject
 228         (
 229             "nuTilda",
 230             runTime_.timeName(),
 231             mesh_,
 232             IOobject::MUST_READ,
 233             IOobject::AUTO_WRITE
 234         ),
 235         mesh_
 236     ),
 237
 238     dTilda_(min(CDES_*delta(), wallDist(mesh_).y())),
 239     muSgs_
 240     (
 241         IOobject
 242         (
 243             "muSgs",
 244             runTime_.timeName(),
 245             mesh_,
 246             IOobject::MUST_READ,
 247             IOobject::AUTO_WRITE
 248         ),
 249         mesh_
 250     ),
 251
 252     alphaSgs_
 253     (
 254         IOobject
 255         (
 256             "alphaSgs",
 257             runTime_.timeName(),
 258             mesh_,
 259             IOobject::MUST_READ,
 260             IOobject::AUTO_WRITE
 261         ),
 262         mesh_
 263     )
 264 {
 265     updateSubGridScaleFields();
 266
 267     printCoeffs();
 268 }
 269
 270
 271 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 272
 273 tmp<volSymmTensorField> SpalartAllmaras::B() const
 274 {
 275     return ((2.0/3.0)*I)*k() - (muSgs_/rho())*dev(twoSymm(fvc::grad(U())));
 276 }
 277
 278
 279 tmp<volSymmTensorField> SpalartAllmaras::devRhoBeff() const
 280 {
 281     return -muEff()*dev(twoSymm(fvc::grad(U())));
 282 }
 283
 284
 285 tmp<volScalarField> SpalartAllmaras::epsilon() const
 286 {
 287     return 2*muEff()/rho()*magSqr(symm(fvc::grad(U())));
 288 }
 289
 290
 291 tmp<fvVectorMatrix> SpalartAllmaras::divDevRhoBeff(volVectorField& U) const
 292 {
 293     return
 294     (
 295       - fvm::laplacian(muEff(), U) - fvc::div(muEff()*dev2(T(fvc::grad(U))))
 296     );
 297 }
 298
 299
 300 void SpalartAllmaras::correct(const tmp<volTensorField>& tgradU)
 301 {
 302     const volTensorField& gradU = tgradU();
 303     LESModel::correct(gradU);
 304
 305     if (mesh_.changing())
 306     {
 307         dTilda_ = min(CDES_*delta(), wallDist(mesh_).y());
 308     }
 309
 310     volScalarField Stilda
 311     (
 312         fv3()*::sqrt(2.0)*mag(skew(gradU)) + fv2()*nuTilda_/sqr(kappa_*dTilda_)
 313     );
 314
 315     tmp<fvScalarMatrix> nuTildaEqn
 316     (
 317         fvm::ddt(rho(), nuTilda_)
 318       + fvm::div(phi(), nuTilda_)
 319       - fvm::laplacian
 320         (
 321             (nuTilda_*rho() + mu())/sigmaNut_,
 322             nuTilda_,
 323             "laplacian(DnuTildaEff,nuTilda)"
 324         )
 325       - rho()*Cb2_/sigmaNut_*magSqr(fvc::grad(nuTilda_))
 326      ==
 327         rho()*Cb1_*Stilda*nuTilda_
 328       - fvm::Sp(rho()*Cw1_*fw(Stilda)*nuTilda_/sqr(dTilda_), nuTilda_)
 329     );
 330
 331     nuTildaEqn().relax();
 332     nuTildaEqn().solve();
 333
 334     bound(nuTilda_, dimensionedScalar("zero", nuTilda_.dimensions(), 0.0));
 335     nuTilda_.correctBoundaryConditions();
 336
 337     updateSubGridScaleFields();
 338 }
 339
 340
 341 bool SpalartAllmaras::read()
 342 {
 343     if (LESModel::read())
 344     {
 345         sigmaNut_.readIfPresent(coeffDict());
 346         Prt_.readIfPresent(coeffDict());
 347         Cb1_.readIfPresent(coeffDict());
 348         Cb2_.readIfPresent(coeffDict());
 349         Cw1_ = Cb1_/sqr(kappa_) + (1.0 + Cb2_)/sigmaNut_;
 350         Cw2_.readIfPresent(coeffDict());
 351         Cw3_.readIfPresent(coeffDict());
 352         Cv1_.readIfPresent(coeffDict());
 353         Cv2_.readIfPresent(coeffDict());
 354         CDES_.readIfPresent(coeffDict());
 355         ck_.readIfPresent(coeffDict());
 356         kappa_.readIfPresent(*this);
 357
 358         return true;
 359     }
 360     else
 361     {
 362         return false;
 363     }
 364 }
 365
 366
 367 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 368
 369 } // End namespace LESModels
 370 } // End namespace compressible
 371 } // End namespace Foam
 372
 373 // ************************************************************************* //