/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | foam-extend: Open Source CFD
   \\    /   O peration     | Version:     4.0
    \\  /    A nd           | Web:         http://www.foam-extend.org
     \\/     M anipulation  | For copyright notice see file Copyright
-------------------------------------------------------------------------------
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
    elasticThermalSolidFoam

Description
    Transient/steady-state segregated finite-volume solver for small strain
    elastic thermal solid bodies. Temperature is solved and then coupled
    displacement is solved.

    Displacement field U is solved for using a total Lagrangian approach,
    also generating the strain tensor field epsilon and stress tensor
    field sigma and temperature field T.

Author
   Philip Cardiff UCD

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

#include "fvCFD.H"
#include "constitutiveModel.H"
#include "thermalModel.H"

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

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

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

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

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

#       include "readSolidMechanicsControls.H"

        int iCorr = 0;
        scalar initialResidual = 1.0;
        scalar relResT = 1.0;
        scalar relResU = 1.0;
        lduSolverPerformance solverPerfU;
        lduSolverPerformance solverPerfT;
        lduMatrix::debug = 0;

        // solve energy equation for temperature
        // the loop is for non-orthogonal corrections
        Info<< "Solving for " << T.name() << nl;
        do
        {
            T.storePrevIter();

            fvScalarMatrix TEqn
            (
                rhoC*fvm::ddt(T) == fvm::laplacian(k, T, "laplacian(k,T)")
            );

            solverPerfT = TEqn.solve();

            T.relax();

#           include "calculateRelResT.H"

            if (iCorr % infoFrequency == 0)
            {
                Info<< "\tCorrector " << iCorr
                    << ", residual = " << solverPerfT.initialResidual()
                    << ", relative res = " << relResT
                    << ", inner iters = " << solverPerfT.nIterations() << endl;
            }
        }
        while
        (
            relResT > convergenceToleranceT
         && ++iCorr < nCorr
        );

        Info<< "Solved for " << T.name()
            << " using " << solverPerfT.solverName()
            << " in " << iCorr << " iterations"
            << ", residual = " << solverPerfT.initialResidual()
            << ", relative res = " << relResT << nl
            << "ExecutionTime = " << runTime.elapsedCpuTime() << " s"
            << ", ClockTime = " << runTime.elapsedClockTime() << " s"
            << endl;

        // Solve momentum equation for displacement
        iCorr = 0;
        volVectorField gradThreeKalphaDeltaT =
            fvc::grad(threeKalpha*(T-T0), "grad(threeKalphaDeltaT)");
        surfaceVectorField threeKalphaDeltaTf =
            mesh.Sf()*threeKalphaf*fvc::interpolate(T-T0, "deltaT");

        Info<< "Solving for " << U.name() << nl;
        do
        {
            U.storePrevIter();

#           include "calculateDivSigmaExp.H"

            // Linear momentum equaiton
            fvVectorMatrix UEqn
            (
                rho*fvm::d2dt2(U)
             ==
                fvm::laplacian(2*muf + lambdaf, U, "laplacian(DU,U)")
              + divSigmaExp
            );

            solverPerfU = UEqn.solve();

            if (aitkenRelax)
            {
#               include "aitkenRelaxation.H"
            }
            else
            {
                U.relax();
            }

            gradU = fvc::grad(U);

#           include "calculateRelResU.H"

            if (iCorr == 0)
            {
                initialResidual = solverPerfU.initialResidual();
            }

            if (iCorr % infoFrequency == 0)
            {
                Info<< "\tCorrector " << iCorr
                    << ", residual = " << solverPerfU.initialResidual()
                    << ", relative res = " << relResU;

                if (aitkenRelax)
                {
                    Info << ", aitken = " << aitkenTheta;
                }
                Info<< ", inner iters = " << solverPerfU.nIterations() << endl;
            }
        }
        while
        (
            iCorr++ == 0
         || (
                relResU > convergenceToleranceU
             && iCorr < nCorr
            )
        );

        Info<< "Solved for " << U.name()
            << " using " << solverPerfU.solverName()
            << " in " << iCorr << " iterations"
            << ", initial res = " << initialResidual
            << ", final res = " << solverPerfU.initialResidual()
            << ", final rel res = " << relResU << nl
            << "ExecutionTime = " << runTime.elapsedCpuTime() << " s"
            << ", ClockTime = " << runTime.elapsedClockTime() << " s"
            << endl;

#       include "calculateEpsilonSigma.H"
#       include "writeFields.H"

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

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

    return(0);
}


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