kOmegaSSTBase.H

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License
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Class
    Foam::kOmegaSST

Description
    Implementation of the k-omega-SST turbulence model for
    incompressible and compressible flows.

    Turbulence model described in:
    \verbatim
        Menter, F. R. & Esch, T. (2001).
        Elements of Industrial Heat Transfer Prediction.
        16th Brazilian Congress of Mechanical Engineering (COBEM).
    \endverbatim

    with updated coefficients from
    \verbatim
        Menter, F. R., Kuntz, M., and Langtry, R. (2003).
        Ten Years of Industrial Experience with the SST Turbulence Model.
        Turbulence, Heat and Mass Transfer 4, ed: K. Hanjalic, Y. Nagano,
        & M. Tummers, Begell House, Inc., 625 - 632.
    \endverbatim

    but with the consistent production terms from the 2001 paper as form in the
    2003 paper is a typo, see
    \verbatim
        http://turbmodels.larc.nasa.gov/sst.html
    \endverbatim

    and the addition of the optional F3 term for rough walls from
    \verbatim
        Hellsten, A. (1998).
        "Some Improvements in Menter’s k-omega-SST turbulence model"
        29th AIAA Fluid Dynamics Conference, AIAA-98-2554.
    \endverbatim

    Note that this implementation is written in terms of alpha diffusion
    coefficients rather than the more traditional sigma (alpha = 1/sigma) so
    that the blending can be applied to all coefficuients in a consistent
    manner.  The paper suggests that sigma is blended but this would not be
    consistent with the blending of the k-epsilon and k-omega models.

    Also note that the error in the last term of equation (2) relating to
    sigma has been corrected.

    Wall-functions are applied in this implementation by using equations (14)
    to specify the near-wall omega as appropriate.

    The blending functions (15) and (16) are not currently used because of the
    uncertainty in their origin, range of applicability and that if y+ becomes
    sufficiently small blending u_tau in this manner clearly becomes nonsense.

    The default model coefficients are
    \verbatim
        kOmegaSSTCoeffs
        {
            alphaK1     0.85;
            alphaK2     1.0;
            alphaOmega1 0.5;
            alphaOmega2 0.856;
            beta1       0.075;
            beta2       0.0828;
            betaStar    0.09;
            gamma1      5/9;
            gamma2      0.44;
            a1          0.31;
            b1          1.0;
            c1          10.0;
            F3          no;
        }
    \endverbatim

SourceFiles
    kOmegaSST.C

\*---------------------------------------------------------------------------*/

#ifndef kOmegaSSTBase_H
#define kOmegaSSTBase_H

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

namespace Foam
{

/*---------------------------------------------------------------------------*\
                           Class kOmegaSST Declaration
\*---------------------------------------------------------------------------*/

template<class MomentumTransportModel, class BasicMomentumTransportModel>
class kOmegaSST
:
    public MomentumTransportModel
{
protected:

    // Protected data

        // Model coefficients

            dimensionedScalar alphaK1_;
            dimensionedScalar alphaK2_;

            dimensionedScalar alphaOmega1_;
            dimensionedScalar alphaOmega2_;

            dimensionedScalar gamma1_;
            dimensionedScalar gamma2_;

            dimensionedScalar beta1_;
            dimensionedScalar beta2_;

            dimensionedScalar betaStar_;

            dimensionedScalar a1_;
            dimensionedScalar b1_;
            dimensionedScalar c1_;

            Switch F3_;


        // Fields

            //- Wall distance
            //  Note: different to wall distance in parent RASModel
            //  which is for near-wall cells only
            const volScalarField& y_;

            volScalarField k_;
            volScalarField omega_;


    // Protected Member Functions

        virtual tmp<volScalarField> F1(const volScalarField& CDkOmega) const;
        virtual tmp<volScalarField> F2() const;
        virtual tmp<volScalarField> F3() const;
        virtual tmp<volScalarField> F23() const;

        tmp<volScalarField> blend
        (
            const volScalarField& F1,
            const dimensionedScalar& psi1,
            const dimensionedScalar& psi2
        ) const
        {
            return F1*(psi1 - psi2) + psi2;
        }

        tmp<volScalarField::Internal> blend
        (
            const volScalarField::Internal& F1,
            const dimensionedScalar& psi1,
            const dimensionedScalar& psi2
        ) const
        {
            return F1*(psi1 - psi2) + psi2;
        }

        tmp<volScalarField> alphaK(const volScalarField& F1) const
        {
            return blend(F1, alphaK1_, alphaK2_);
        }

        tmp<volScalarField> alphaOmega(const volScalarField& F1) const
        {
            return blend(F1, alphaOmega1_, alphaOmega2_);
        }

        tmp<volScalarField::Internal> beta
        (
            const volScalarField::Internal& F1
        ) const
        {
            return blend(F1, beta1_, beta2_);
        }

        tmp<volScalarField::Internal> gamma
        (
            const volScalarField::Internal& F1
        ) const
        {
            return blend(F1, gamma1_, gamma2_);
        }

        virtual void correctNut
        (
            const volScalarField& S2,
            const volScalarField& F2
        );

        virtual void correctNut();

        //- Return k production rate
        virtual tmp<volScalarField::Internal> Pk
        (
            const volScalarField::Internal& G
        ) const;

        //- Return epsilon/k which for standard RAS is betaStar*omega
        virtual tmp<volScalarField::Internal> epsilonByk
        (
            const volScalarField::Internal& F1,
            const volScalarField::Internal& F2
        ) const;

        virtual tmp<fvScalarMatrix> kSource() const;

        virtual tmp<fvScalarMatrix> omegaSource() const;

        virtual tmp<fvScalarMatrix> Qsas
        (
            const volScalarField::Internal& S2,
            const volScalarField::Internal& gamma,
            const volScalarField::Internal& beta
        ) const;


public:

    typedef typename BasicMomentumTransportModel::alphaField alphaField;
    typedef typename BasicMomentumTransportModel::rhoField rhoField;
    typedef typename BasicMomentumTransportModel::transportModel transportModel;


    // Constructors

        //- Construct from components
        kOmegaSST
        (
            const word& type,
            const alphaField& alpha,
            const rhoField& rho,
            const volVectorField& U,
            const surfaceScalarField& alphaRhoPhi,
            const surfaceScalarField& phi,
            const transportModel& transport
        );

        //- Disallow default bitwise copy construction
        kOmegaSST(const kOmegaSST&) = delete;


    //- Destructor
    virtual ~kOmegaSST()
    {}


    // Member Functions

        //- Re-read model coefficients if they have changed
        virtual bool read();

        //- Return the effective diffusivity for k
        tmp<volScalarField> DkEff(const volScalarField& F1) const
        {
            return volScalarField::New
            (
                "DkEff",
                alphaK(F1)*this->nut_ + this->nu()
            );
        }

        //- Return the effective diffusivity for omega
        tmp<volScalarField> DomegaEff(const volScalarField& F1) const
        {
            return volScalarField::New
            (
                "DomegaEff",
                alphaOmega(F1)*this->nut_ + this->nu()
            );
        }

        //- Return the turbulence kinetic energy
        virtual tmp<volScalarField> k() const
        {
            return k_;
        }

        //- Return the turbulence kinetic energy dissipation rate
        virtual tmp<volScalarField> epsilon() const
        {
            return volScalarField::New
            (
                "epsilon",
                betaStar_*k_*omega_,
                omega_.boundaryField().types()
            );
        }

        //- Return the turbulence kinetic energy dissipation rate
        virtual tmp<volScalarField> omega() const
        {
            return omega_;
        }

        //- Solve the turbulence equations and correct the turbulence viscosity
        virtual void correct();


    // Member Operators

        //- Disallow default bitwise assignment
        void operator=(const kOmegaSST&) = delete;
};


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

} // End namespace Foam

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
#ifdef NoRepository
    #include "kOmegaSSTBase.C"
#endif

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
#endif

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