/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | Copyright (C) 2011-2013 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/>.

Application
    pisoFoam

Description
    Transient solver for incompressible flow.

    Turbulence modelling is generic, i.e. laminar, RAS or LES may be selected.

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

#include "fvCFD.H"
#include "singlePhaseTransportModel.H"
#include "IncompressibleTurbulenceModel.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.loop())
    {
        Info<< "Time = " << runTime.timeName() << nl << endl;

        #include "readPISOControls.H"
        #include "CourantNo.H"

        // Pressure-velocity PISO corrector
        {
            // Momentum predictor

            fvVectorMatrix UEqn
            (
                fvm::ddt(U)
              + fvm::div(phi, U)
              + turbulence->divDevReff(U)
            );

            UEqn.relax();

            if (momentumPredictor)
            {
                solve(UEqn == -fvc::grad(p));
            }

            // --- PISO loop

            for (int corr=0; corr<nCorr; corr++)
            {
                volScalarField rAU(1.0/UEqn.A());

                volVectorField HbyA("HbyA", U);
                HbyA = rAU*UEqn.H();
                surfaceScalarField phiHbyA
                (
                    "phiHbyA",
                    (fvc::interpolate(HbyA) & mesh.Sf())
                  + fvc::ddtCorr(rAU, U, phi)
                );

                adjustPhi(phiHbyA, U, p);

                // Non-orthogonal pressure corrector loop
                for (int nonOrth=0; nonOrth<=nNonOrthCorr; nonOrth++)
                {
                    // Pressure corrector

                    fvScalarMatrix pEqn
                    (
                        fvm::laplacian(rAU, p) == fvc::div(phiHbyA)
                    );

                    pEqn.setReference(pRefCell, pRefValue);

                    if
                    (
                        corr == nCorr-1
                     && nonOrth == nNonOrthCorr
                    )
                    {
                        pEqn.solve(mesh.solver("pFinal"));
                    }
                    else
                    {
                        pEqn.solve();
                    }

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

                #include "continuityErrs.H"

                U = HbyA - rAU*fvc::grad(p);
                U.correctBoundaryConditions();
            }
        }

        laminarTransport.correct();
        turbulence->correct();

        runTime.write();

        Info<< "ExecutionTime = " << runTime.elapsedCpuTime() << " s"
            << "  ClockTime = " << runTime.elapsedClockTime() << " s"
            << nl << endl;
    }

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

    return 0;
}


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