/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | Copyright (C) 2011-2012 OpenFOAM Foundation
     \\/     M anipulation  |
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.

    OpenFOAM is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.

    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.

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

#include "realizableKE.H"
#include "addToRunTimeSelectionTable.H"

#include "backwardsCompatibilityWallFunctions.H"

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

namespace Foam
{
namespace incompressible
{
namespace RASModels
{

// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //

defineTypeNameAndDebug(realizableKE, 0);
addToRunTimeSelectionTable(RASModel, realizableKE, dictionary);

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

tmp<volScalarField> realizableKE::rCmu
(
    const volTensorField& gradU,
    const volScalarField& S2,
    const volScalarField& magS
)
{
    tmp<volSymmTensorField> tS = dev(symm(gradU));
    const volSymmTensorField& S = tS();

    tmp<volScalarField> W
    (
        (2*sqrt(2.0))*((S&S)&&S)
       /(
            magS*S2
          + dimensionedScalar("small", dimensionSet(0, 0, -3, 0, 0), SMALL)
        )
    );

    tS.clear();

    tmp<volScalarField> phis
    (
        (1.0/3.0)*acos(min(max(sqrt(6.0)*W, -scalar(1)), scalar(1)))
    );
    tmp<volScalarField> As = sqrt(6.0)*cos(phis);
    tmp<volScalarField> Us = sqrt(S2/2.0 + magSqr(skew(gradU)));

    return 1.0/(A0_ + As*Us*k_/epsilon_);
}


tmp<volScalarField> realizableKE::rCmu
(
    const volTensorField& gradU
)
{
    const volScalarField S2(2*magSqr(dev(symm(gradU))));
    tmp<volScalarField> magS = sqrt(S2);
    return rCmu(gradU, S2, magS);
}


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

realizableKE::realizableKE
(
    const volVectorField& U,
    const surfaceScalarField& phi,
    transportModel& transport,
    const word& turbulenceModelName,
    const word& modelName
)
:
    RASModel(modelName, U, phi, transport, turbulenceModelName),

    Cmu_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "Cmu",
            coeffDict_,
            0.09
        )
    ),
    A0_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "A0",
            coeffDict_,
            4.0
        )
    ),
    C2_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "C2",
            coeffDict_,
            1.9
        )
    ),
    sigmak_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "sigmak",
            coeffDict_,
            1.0
        )
    ),
    sigmaEps_
    (
        dimensioned<scalar>::lookupOrAddToDict
        (
            "sigmaEps",
            coeffDict_,
            1.2
        )
    ),

    k_
    (
        IOobject
        (
            "k",
            runTime_.timeName(),
            mesh_,
            IOobject::NO_READ,
            IOobject::AUTO_WRITE
        ),
        autoCreateK("k", mesh_)
    ),
    epsilon_
    (
        IOobject
        (
            "epsilon",
            runTime_.timeName(),
            mesh_,
            IOobject::NO_READ,
            IOobject::AUTO_WRITE
        ),
        autoCreateEpsilon("epsilon", mesh_)
    ),
    nut_
    (
        IOobject
        (
            "nut",
            runTime_.timeName(),
            mesh_,
            IOobject::NO_READ,
            IOobject::AUTO_WRITE
        ),
        autoCreateNut("nut", mesh_)
    )
{
    bound(k_, kMin_);
    bound(epsilon_, epsilonMin_);

    nut_ = rCmu(fvc::grad(U_))*sqr(k_)/epsilon_;
    nut_.correctBoundaryConditions();

    printCoeffs();
}


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

tmp<volSymmTensorField> realizableKE::R() const
{
    return tmp<volSymmTensorField>
    (
        new volSymmTensorField
        (
            IOobject
            (
                "R",
                runTime_.timeName(),
                mesh_,
                IOobject::NO_READ,
                IOobject::NO_WRITE
            ),
            ((2.0/3.0)*I)*k_ - nut_*twoSymm(fvc::grad(U_)),
            k_.boundaryField().types()
        )
    );
}


tmp<volSymmTensorField> realizableKE::devReff() const
{
    return tmp<volSymmTensorField>
    (
        new volSymmTensorField
        (
            IOobject
            (
                "devRhoReff",
                runTime_.timeName(),
                mesh_,
                IOobject::NO_READ,
                IOobject::NO_WRITE
            ),
           -nuEff()*dev(twoSymm(fvc::grad(U_)))
        )
    );
}


tmp<fvVectorMatrix> realizableKE::divDevReff(volVectorField& U) const
{
    return
    (
      - fvm::laplacian(nuEff(), U)
      - fvc::div(nuEff()*dev(T(fvc::grad(U))))
    );
}


tmp<fvVectorMatrix> realizableKE::divDevRhoReff
(
    const volScalarField& rho,
    volVectorField& U
) const
{
    volScalarField muEff("muEff", rho*nuEff());

    return
    (
      - fvm::laplacian(muEff, U)
      - fvc::div(muEff*dev(T(fvc::grad(U))))
    );
}


bool realizableKE::read()
{
    if (RASModel::read())
    {
        Cmu_.readIfPresent(coeffDict());
        A0_.readIfPresent(coeffDict());
        C2_.readIfPresent(coeffDict());
        sigmak_.readIfPresent(coeffDict());
        sigmaEps_.readIfPresent(coeffDict());

        return true;
    }
    else
    {
        return false;
    }
}


void realizableKE::correct()
{
    RASModel::correct();

    if (!turbulence_)
    {
        return;
    }

    const volTensorField gradU(fvc::grad(U_));
    const volScalarField S2(2*magSqr(dev(symm(gradU))));
    const volScalarField magS(sqrt(S2));

    const volScalarField eta(magS*k_/epsilon_);
    tmp<volScalarField> C1 = max(eta/(scalar(5) + eta), scalar(0.43));

    volScalarField G("RASModel::G", nut_*S2);

    // Update epsilon and G at the wall
    epsilon_.boundaryField().updateCoeffs();


    // Dissipation equation
    tmp<fvScalarMatrix> epsEqn
    (
        fvm::ddt(epsilon_)
      + fvm::div(phi_, epsilon_)
      - fvm::Sp(fvc::div(phi_), epsilon_)
      - fvm::laplacian(DepsilonEff(), epsilon_)
     ==
        C1*magS*epsilon_
      - fvm::Sp
        (
            C2_*epsilon_/(k_ + sqrt(nu()*epsilon_)),
            epsilon_
        )
    );

    epsEqn().relax();

    epsEqn().boundaryManipulate(epsilon_.boundaryField());

    solve(epsEqn);
    bound(epsilon_, epsilonMin_);


    // Turbulent kinetic energy equation
    tmp<fvScalarMatrix> kEqn
    (
        fvm::ddt(k_)
      + fvm::div(phi_, k_)
      - fvm::Sp(fvc::div(phi_), k_)
      - fvm::laplacian(DkEff(), k_)
     ==
        G - fvm::Sp(epsilon_/k_, k_)
    );

    kEqn().relax();
    solve(kEqn);
    bound(k_, kMin_);


    // Re-calculate viscosity
    nut_ = rCmu(gradU, S2, magS)*sqr(k_)/epsilon_;
    nut_.correctBoundaryConditions();
}


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

} // End namespace RASModels
} // End namespace incompressible
} // End namespace Foam

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