/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  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
    channelFoam

Description
    Incompressible LES solver for flow in a channel.

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

#include "fvCFD.H"
#include "singlePhaseTransportModel.H"
#include "LESModel.H"
#include "IFstream.H"
#include "OFstream.H"
#include "Random.H"

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

int main(int argc, char *argv[])
{
    #include "setRootCase.H"
    #include "createTime.H"
    #include "createMesh.H"
    #include "readTransportProperties.H"
    #include "createFields.H"
    #include "initContinuityErrs.H"
    #include "createGradP.H"

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

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

        #include "readPISOControls.H"

        #include "CourantNo.H"

        sgsModel->correct();

        fvVectorMatrix UEqn
        (
            fvm::ddt(U)
          + fvm::div(phi, U)
          + sgsModel->divDevBeff(U)
         ==
            flowDirection*gradP
        );

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


        // --- PISO loop

        volScalarField rUA = 1.0/UEqn.A();

        for (int corr = 0; corr < nCorr; corr++)
        {
            U = rUA*UEqn.H();
            phi = (fvc::interpolate(U) & mesh.Sf())
                + fvc::ddtPhiCorr(rUA, U, phi);

            adjustPhi(phi, U, p);

            for (int nonOrth=0; nonOrth<=nNonOrthCorr; nonOrth++)
            {
                fvScalarMatrix pEqn
                (
                    fvm::laplacian(rUA, p) == fvc::div(phi)
                );

                pEqn.setReference(pRefCell, pRefValue);

                if (corr == nCorr-1 && nonOrth == nNonOrthCorr)
                {
                    pEqn.solve(mesh.solutionDict().solver(p.name() + "Final"));
                }
                else
                {
                    pEqn.solve(mesh.solutionDict().solver(p.name()));
                }

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

            #include "continuityErrs.H"

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


        // Correct driving force for a constant mass flow rate

        // Extract the velocity in the flow direction
        dimensionedScalar magUbarStar =
            (flowDirection & U)().weightedAverage(mesh.V());

        // Calculate the pressure gradient increment needed to
        // adjust the average flow-rate to the correct value
        dimensionedScalar gragPplus =
            (magUbar - magUbarStar)/rUA.weightedAverage(mesh.V());

        U += flowDirection*rUA*gragPplus;

        gradP += gragPplus;

        Info<< "Uncorrected Ubar = " << magUbarStar.value() << tab
            << "pressure gradient = " << gradP.value() << endl;

        runTime.write();

        #include "writeGradP.H"

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

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

    return 0;
}


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