/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | foam-extend: Open Source CFD
   \\    /   O peration     |
    \\  /    A nd           | For copyright notice see file Copyright
     \\/     M anipulation  |
-------------------------------------------------------------------------------
License
    This file is part of foam-extend.

    foam-extend 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.

    foam-extend 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 foam-extend.  If not, see <http://www.gnu.org/licenses/>.

Application
    viscoelasticFluidFoam

Description
    Transient solver for incompressible, laminar flow of viscoelastic fluids.

Author
    Jovani L. Favero and Hrvoje Jasak. All rights reserved

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

#include "fvCFD.H"
#include "viscoelasticModel.H"

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

int main(int argc, char *argv[])
{

#   include "setRootCase.H"

#   include "createTime.H"
#   include "createMesh.H"
#   include "createFields.H"
#   include "initContinuityErrs.H"

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

    Info<< "\nStarting time loop\n" << endl;

    while (runTime.run())
    {

#       include "readPISOControls.H"
#       include "readTimeControls.H"
#       include "CourantNo.H"
#       include "setDeltaT.H"

        runTime++;

        Info<< "Time = " << runTime.timeName() << nl << endl;

        // Pressure-velocity SIMPLE corrector loop
        for (int corr = 0; corr < nCorr; corr++)
        {
            // Momentum predictor

            tmp<fvVectorMatrix> UEqn
            (
                fvm::ddt(U)
              + fvm::div(phi, U)
              - visco.divTau(U)
            );

            UEqn().relax();

            solve(UEqn() == -fvc::grad(p));

            p.boundaryField().updateCoeffs();
            volScalarField rUA = 1.0/UEqn().A();
            U = rUA*UEqn().H();
            UEqn.clear();
            phi = fvc::interpolate(U) & mesh.Sf();
            adjustPhi(phi, U, p);

            // Store pressure for under-relaxation
            p.storePrevIter();

            // Non-orthogonal pressure corrector loop
            for (int nonOrth=0; nonOrth<=nNonOrthCorr; nonOrth++)
            {
                fvScalarMatrix pEqn
                (
                    fvm::laplacian(rUA, p) == fvc::div(phi)
                );

                pEqn.setReference(pRefCell, pRefValue);
                pEqn.solve();

                if (nonOrth == nNonOrthCorr)
                {
                    phi -= pEqn.flux();
                }
            }

#           include "continuityErrs.H"

            // Explicitly relax pressure for momentum corrector
            p.relax();

            // Momentum corrector
            U -= rUA*fvc::grad(p);
            U.correctBoundaryConditions();

            visco.correct();
        }

        runTime.write();

        Info<< "ExecutionTime = "
            << runTime.elapsedCpuTime()
            << " s\n\n" << endl;
    }

    Info<< "End\n" << endl;

    return(0);
}


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