kOmegaSSTBase.C

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  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
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#include "kOmegaSSTBase.H"
#include "fvOptions.H"
#include "bound.H"
#include "wallDist.H"

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

namespace Foam
{

// * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * * //

template<class TurbulenceModel, class BasicTurbulenceModel>
tmp<volScalarField>
kOmegaSST<TurbulenceModel, BasicTurbulenceModel>::kOmegaSST::F1
(
    const volScalarField& CDkOmega
) const
{
    tmp<volScalarField> CDkOmegaPlus = max
    (
        CDkOmega,
        dimensionedScalar("1.0e-10", dimless/sqr(dimTime), 1.0e-10)
    );

    tmp<volScalarField> arg1 = min
    (
        min
        (
            max
            (
                (scalar(1)/betaStar_)*sqrt(k_)/(omega_*y_),
                scalar(500)*(this->mu()/this->rho_)/(sqr(y_)*omega_)
            ),
            (4*alphaOmega2_)*k_/(CDkOmegaPlus*sqr(y_))
        ),
        scalar(10)
    );

    return tanh(pow4(arg1));
}

template<class TurbulenceModel, class BasicTurbulenceModel>
tmp<volScalarField>
kOmegaSST<TurbulenceModel, BasicTurbulenceModel>::kOmegaSST::F2() const
{
    tmp<volScalarField> arg2 = min
    (
        max
        (
            (scalar(2)/betaStar_)*sqrt(k_)/(omega_*y_),
            scalar(500)*(this->mu()/this->rho_)/(sqr(y_)*omega_)
        ),
        scalar(100)
    );

    return tanh(sqr(arg2));
}

template<class TurbulenceModel, class BasicTurbulenceModel>
tmp<volScalarField>
kOmegaSST<TurbulenceModel, BasicTurbulenceModel>::kOmegaSST::F3() const
{
    tmp<volScalarField> arg3 = min
    (
        150*(this->mu()/this->rho_)/(omega_*sqr(y_)),
        scalar(10)
    );

    return 1 - tanh(pow4(arg3));
}

template<class TurbulenceModel, class BasicTurbulenceModel>
tmp<volScalarField>
kOmegaSST<TurbulenceModel, BasicTurbulenceModel>::kOmegaSST::F23() const
{
    tmp<volScalarField> f23(F2());

    if (F3_)
    {
        f23.ref() *= F3();
    }

    return f23;
}


template<class TurbulenceModel, class BasicTurbulenceModel>
void kOmegaSST<TurbulenceModel, BasicTurbulenceModel>::correctNut
(
    const volScalarField& S2,
    const volScalarField& F2
)
{
    this->nut_ = a1_*k_/max(a1_*omega_, b1_*F2*sqrt(S2));
    this->nut_.correctBoundaryConditions();
    fv::options::New(this->mesh_).correct(this->nut_);

    BasicTurbulenceModel::correctNut();
}


// * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //

template<class TurbulenceModel, class BasicTurbulenceModel>
void kOmegaSST<TurbulenceModel, BasicTurbulenceModel>::correctNut()
{
    correctNut(2*magSqr(symm(fvc::grad(this->U_))), F23());
}


template<class TurbulenceModel, class BasicTurbulenceModel>
tmp<volScalarField> kOmegaSST<TurbulenceModel, BasicTurbulenceModel>::epsilonByk
(
    const volScalarField& F1,
    const volScalarField& F2
) const
{
    return betaStar_*omega_;
}


template<class TurbulenceModel, class BasicTurbulenceModel>
tmp<fvScalarMatrix>
kOmegaSST<TurbulenceModel, BasicTurbulenceModel>::kSource() const
{
    return tmp<fvScalarMatrix>
    (
        new fvScalarMatrix
        (
            k_,
            dimVolume*this->rho_.dimensions()*k_.dimensions()/dimTime
        )
    );
}


template<class TurbulenceModel, class BasicTurbulenceModel>
tmp<fvScalarMatrix>
kOmegaSST<TurbulenceModel, BasicTurbulenceModel>::omegaSource() const
{
    return tmp<fvScalarMatrix>
    (
        new fvScalarMatrix
        (
            omega_,
            dimVolume*this->rho_.dimensions()*omega_.dimensions()/dimTime
        )
    );
}


template<class TurbulenceModel, class BasicTurbulenceModel>
tmp<fvScalarMatrix> kOmegaSST<TurbulenceModel, BasicTurbulenceModel>::Qsas
(
    const volScalarField& S2,
    const volScalarField& gamma,
    const volScalarField& beta
) const
{
    return tmp<fvScalarMatrix>
    (
        new fvScalarMatrix
        (
            omega_,
            dimVolume*this->rho_.dimensions()*omega_.dimensions()/dimTime
        )
    );
}


// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //

template<class TurbulenceModel, class BasicTurbulenceModel>
kOmegaSST<TurbulenceModel, BasicTurbulenceModel>::kOmegaSST
(
    const word& type,
    const alphaField& alpha,
    const rhoField& rho,
    const volVectorField& U,
    const surfaceScalarField& alphaRhoPhi,
    const surfaceScalarField& phi,
    const transportModel& transport,
    const word& propertiesName
)
:
    TurbulenceModel
    (
        type,
        alpha,
        rho,
        U,
        alphaRhoPhi,
        phi,
        transport,
        propertiesName
    ),

    alphaK1_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "alphaK1",
            this->coeffDict_,
            0.85
        )
    ),
    alphaK2_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "alphaK2",
            this->coeffDict_,
            1.0
        )
    ),
    alphaOmega1_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "alphaOmega1",
            this->coeffDict_,
            0.5
        )
    ),
    alphaOmega2_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "alphaOmega2",
            this->coeffDict_,
            0.856
        )
    ),
    gamma1_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "gamma1",
            this->coeffDict_,
            5.0/9.0
        )
    ),
    gamma2_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "gamma2",
            this->coeffDict_,
            0.44
        )
    ),
    beta1_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "beta1",
            this->coeffDict_,
            0.075
        )
    ),
    beta2_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "beta2",
            this->coeffDict_,
            0.0828
        )
    ),
    betaStar_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "betaStar",
            this->coeffDict_,
            0.09
        )
    ),
    a1_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "a1",
            this->coeffDict_,
            0.31
        )
    ),
    b1_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "b1",
            this->coeffDict_,
            1.0
        )
    ),
    c1_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "c1",
            this->coeffDict_,
            10.0
        )
    ),
    F3_
    (
        Switch::lookupOrAddToDict
        (
            "F3",
            this->coeffDict_,
            false
        )
    ),

    y_(wallDist::New(this->mesh_).y()),

    k_
    (
        IOobject
        (
            IOobject::groupName("k", U.group()),
            this->runTime_.timeName(),
            this->mesh_,
            IOobject::MUST_READ,
            IOobject::AUTO_WRITE
        ),
        this->mesh_
    ),
    omega_
    (
        IOobject
        (
            IOobject::groupName("omega", U.group()),
            this->runTime_.timeName(),
            this->mesh_,
            IOobject::MUST_READ,
            IOobject::AUTO_WRITE
        ),
        this->mesh_
    )
{
    bound(k_, this->kMin_);
    bound(omega_, this->omegaMin_);
}


// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //

template<class TurbulenceModel, class BasicTurbulenceModel>
bool kOmegaSST<TurbulenceModel, BasicTurbulenceModel>::read()
{
    if (BasicTurbulenceModel::read())
    {
        alphaK1_.readIfPresent(this->coeffDict());
        alphaK2_.readIfPresent(this->coeffDict());
        alphaOmega1_.readIfPresent(this->coeffDict());
        alphaOmega2_.readIfPresent(this->coeffDict());
        gamma1_.readIfPresent(this->coeffDict());
        gamma2_.readIfPresent(this->coeffDict());
        beta1_.readIfPresent(this->coeffDict());
        beta2_.readIfPresent(this->coeffDict());
        betaStar_.readIfPresent(this->coeffDict());
        a1_.readIfPresent(this->coeffDict());
        b1_.readIfPresent(this->coeffDict());
        c1_.readIfPresent(this->coeffDict());
        F3_.readIfPresent("F3", this->coeffDict());

        return true;
    }
    else
    {
        return false;
    }
}


template<class TurbulenceModel, class BasicTurbulenceModel>
void kOmegaSST<TurbulenceModel, BasicTurbulenceModel>::correct()
{
    if (!this->turbulence_)
    {
        return;
    }

    // Local references
    const alphaField& alpha = this->alpha_;
    const rhoField& rho = this->rho_;
    const surfaceScalarField& alphaRhoPhi = this->alphaRhoPhi_;
    const volVectorField& U = this->U_;
    volScalarField& nut = this->nut_;
    fv::options& fvOptions(fv::options::New(this->mesh_));

    BasicTurbulenceModel::correct();

    volScalarField divU(fvc::div(fvc::absolute(this->phi(), U)));

    tmp<volTensorField> tgradU = fvc::grad(U);
    volScalarField S2(2*magSqr(symm(tgradU())));
    volScalarField GbyNu((tgradU() && dev(twoSymm(tgradU()))));
    volScalarField G(this->GName(), nut*GbyNu);
    tgradU.clear();

    // Update omega and G at the wall
    omega_.boundaryFieldRef().updateCoeffs();

    volScalarField CDkOmega
    (
        (2*alphaOmega2_)*(fvc::grad(k_) & fvc::grad(omega_))/omega_
    );

    volScalarField F1(this->F1(CDkOmega));
    volScalarField F23(this->F23());

    {
        volScalarField gamma(this->gamma(F1));
        volScalarField beta(this->beta(F1));

        // Turbulent frequency equation
        tmp<fvScalarMatrix> omegaEqn
        (
            fvm::ddt(alpha, rho, omega_)
          + fvm::div(alphaRhoPhi, omega_)
          - fvm::laplacian(alpha*rho*DomegaEff(F1), omega_)
         ==
            alpha*rho*gamma
           *min
            (
                GbyNu,
                (c1_/a1_)*betaStar_*omega_*max(a1_*omega_, b1_*F23*sqrt(S2))
            )
          - fvm::SuSp((2.0/3.0)*alpha*rho*gamma*divU, omega_)
          - fvm::Sp(alpha*rho*beta*omega_, omega_)
          - fvm::SuSp
            (
                alpha*rho*(F1 - scalar(1))*CDkOmega/omega_,
                omega_
            )
          + Qsas(S2, gamma, beta)
          + omegaSource()
          + fvOptions(alpha, rho, omega_)
        );

        omegaEqn.ref().relax();
        fvOptions.constrain(omegaEqn.ref());
        omegaEqn.ref().boundaryManipulate(omega_.boundaryFieldRef());
        solve(omegaEqn);
        fvOptions.correct(omega_);
        bound(omega_, this->omegaMin_);
    }

    // Turbulent kinetic energy equation
    tmp<fvScalarMatrix> kEqn
    (
        fvm::ddt(alpha, rho, k_)
      + fvm::div(alphaRhoPhi, k_)
      - fvm::laplacian(alpha*rho*DkEff(F1), k_)
     ==
        min(alpha*rho*G, (c1_*betaStar_)*alpha*rho*k_*omega_)
      - fvm::SuSp((2.0/3.0)*alpha*rho*divU, k_)
      - fvm::Sp(alpha*rho*epsilonByk(F1, F23), k_)
      + kSource()
      + fvOptions(alpha, rho, k_)
    );

    kEqn.ref().relax();
    fvOptions.constrain(kEqn.ref());
    solve(kEqn);
    fvOptions.correct(k_);
    bound(k_, this->kMin_);

    correctNut(S2, F23);
}


// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

} // End namespace Foam

// ************************************************************************* //