icoFoam.C

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/*---------------------------------------------------------------------------*\
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-------------------------------------------------------------------------------
    Copyright (C) 2011-2016 OpenFOAM Foundation
    Copyright (C) 2019 OpenCFD Ltd.
-------------------------------------------------------------------------------
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
    icoFoam
 
Group
    grpIncompressibleSolvers
 
Description
    Transient solver for incompressible, laminar flow of Newtonian fluids.
 
    \heading Solver details
    The solver uses the PISO algorithm to solve the continuity equation:
 
        \f[
            \div \vec{U} = 0
        \f]
 
    and momentum equation:
 
        \f[
            \ddt{\vec{U}}
          + \div \left( \vec{U} \vec{U} \right)
          - \div \left(\nu \grad \vec{U} \right)
          = - \grad p
        \f]
 
    Where:
    \vartable
        \vec{U} | Velocity
        p       | Pressure
    \endvartable
 
    \heading Required fields
    \plaintable
        U       | Velocity [m/s]
        p       | Kinematic pressure, p/rho [m2/s2]
    \endplaintable
 
\*---------------------------------------------------------------------------*/
 
#include "fvCFD.H"
#include "pisoControl.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
int main(int argc, char *argv[])
{
    argList::addNote
    (
        "Transient solver for incompressible, laminar flow"
        " of Newtonian fluids."
    );
 
    #include "postProcess.H"
 
    #include "addCheckCaseOptions.H"
    #include "setRootCaseLists.H"
    #include "createTime.H"
    #include "createMesh.H"
 
    pisoControl piso(mesh);
 
    #include "createFields.H"
    #include "initContinuityErrs.H"
 
    // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
    Info<< "\nStarting time loop\n" << endl;
 
    while (runTime.loop())
    {
        Info<< "Time = " << runTime.timeName() << nl << endl;
 
        #include "CourantNo.H"
 
        // Momentum predictor
 
        fvVectorMatrix UEqn
        (
            fvm::ddt(U)
          + fvm::div(phi, U)
          - fvm::laplacian(nu, U)
        );
 
        if (piso.momentumPredictor())
        {
            solve(UEqn == -fvc::grad(p));
        }
 
        // --- PISO loop
        while (piso.correct())
        {
            volScalarField rAU(1.0/UEqn.A());
            volVectorField HbyA(constrainHbyA(rAU*UEqn.H(), U, p));
            surfaceScalarField phiHbyA
            (
                "phiHbyA",
                fvc::flux(HbyA)
              + fvc::interpolate(rAU)*fvc::ddtCorr(U, phi)
            );
 
            adjustPhi(phiHbyA, U, p);
 
            // Update the pressure BCs to ensure flux consistency
            constrainPressure(p, U, phiHbyA, rAU);
 
            // Non-orthogonal pressure corrector loop
            while (piso.correctNonOrthogonal())
            {
                // Pressure corrector
 
                fvScalarMatrix pEqn
                (
                    fvm::laplacian(rAU, p) == fvc::div(phiHbyA)
                );
 
                pEqn.setReference(pRefCell, pRefValue);
 
                pEqn.solve(mesh.solver(p.select(piso.finalInnerIter())));
 
                if (piso.finalNonOrthogonalIter())
                {
                    phi = phiHbyA - pEqn.flux();
                }
            }
 
            #include "continuityErrs.H"
 
            U = HbyA - rAU*fvc::grad(p);
            U.correctBoundaryConditions();
        }
 
        runTime.write();
 
        runTime.printExecutionTime(Info);
    }
 
    Info<< "End\n" << endl;
 
    return 0;
}
 
 
// ************************************************************************* //