[srv537]

I was using fluent and i just started using OpenFoam. i have added Energy equation in pimpleFoam, i have compared fluent laminar result with it and it is working fine and soon i will compare turbulent result.

I am new in C++ language and OpenFoam so i have some kind of fear that may be i have modified pimpleFoam inaccurately and fortunately i am getting the correct result.

Here is my code, please check it and if there is any mistake please correct me, it will be very helpful for me.

mypimpleFoam.C

PHP Code:


int main(int argc, char *argv[])
{
    #include "postProcess.H"

    #include "setRootCase.H"
    #include "createTime.H"
    #include "createMesh.H"
    #include "createControl.H"
    #include "createTimeControls.H"
    #include "createFields.H"
    #include "createFvOptions.H"
    #include "initContinuityErrs.H"

    turbulence->validate();

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

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

    while (runTime.run())
    {
        #include "readTimeControls.H"
        #include "CourantNo.H"
        #include "setDeltaT.H"

        runTime++;

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

        // --- Pressure-velocity PIMPLE corrector loop
        while (pimple.loop())
        {
            #include "UEqn.H"

            // --- Pressure corrector loop
            while (pimple.correct())
            {
                #include "pEqn.H"
            }

            if (pimple.turbCorr())
            {
                laminarTransport.correct();
                turbulence->correct();
            }
        }


 #include "TEqn.H"


// Calculates dT/dy
        Info<< "Calculating gradT" << endl;

label patchi = mesh.boundaryMesh().findPatchID("HEATEDWALL");

// calculate (dT/dy)_wall
//gradT.boundaryField()[patchi]=T.boundaryField()[patchi].snGrad();
gradT.boundaryFieldRef()[patchi]=T.boundaryFieldRef()[patchi].snGrad();

        scalar area1 = gSum(mesh.magSf().boundaryField()[patchi]);
                scalar sumField1 = 0;

                if (area1 > 0)
                {
                    sumField1 = gSum
                    (
                        mesh.magSf().boundaryField()[patchi]
                      * gradT.boundaryField()[patchi]
                    )/ area1;
                }

             Info<< "    Average of gradT over patch 1 = " << sumField1 << endl;


             

//label patchi = mesh.boundaryMesh().findPatchID("myPatch");
//gradT.boundaryField()[patchi]=T.boundaryField()[patchi].snGrad();


        runTime.write();

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

    Info<< "End\n" << endl;

    return 0;
} 


UEqn.H

PHP Code:

// Solve the Momentum equation

MRF.correctBoundaryVelocity(U);

tmp<fvVectorMatrix> tUEqn
(
    fvm::ddt(U) + fvm::div(phi, U)
  + MRF.DDt(U)
  + turbulence->divDevReff(U)
 ==
    fvOptions(U)
);
fvVectorMatrix& UEqn = tUEqn.ref();

UEqn.relax();

fvOptions.constrain(UEqn);

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

    fvOptions.correct(U);
} 


PEqn.H

PHP Code:

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)
);

MRF.makeRelative(phiHbyA);

adjustPhi(phiHbyA, U, p);

tmp<volScalarField> rAtU(rAU);

if (pimple.consistent())
{
    rAtU = 1.0/max(1.0/rAU - UEqn.H1(), 0.1/rAU);
    phiHbyA +=
        fvc::interpolate(rAtU() - rAU)*fvc::snGrad(p)*mesh.magSf();
    HbyA -= (rAU - rAtU())*fvc::grad(p);
}

if (pimple.nCorrPISO() <= 1)
{
    tUEqn.clear();
}

// Update the pressure BCs to ensure flux consistency
constrainPressure(p, U, phiHbyA, rAtU(), MRF);

// Non-orthogonal pressure corrector loop
while (pimple.correctNonOrthogonal())
{
    // Pressure corrector
    fvScalarMatrix pEqn
    (
        fvm::laplacian(rAtU(), p) == fvc::div(phiHbyA)
    );

    pEqn.setReference(pRefCell, pRefValue);

    pEqn.solve(mesh.solver(p.select(pimple.finalInnerIter())));

    if (pimple.finalNonOrthogonalIter())
    {
        phi = phiHbyA - pEqn.flux();
    }
}

#include "continuityErrs.H"

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

U = HbyA - rAtU()*fvc::grad(p);
U.correctBoundaryConditions();
fvOptions.correct(U); 


TEqn.H

PHP Code:


// Solve the ENRRGY (Temp) equation



    kappat = turbulence->nut()/Prt;
    kappat.correctBoundaryConditions();
    
//    volScalarField kappaEff("kappaEff", turbulence->nu()/Pr + kappat);

    volScalarField kappaEff("kappaEff", nu/Pr + kappat);

    fvScalarMatrix TEqn
    (
       fvm::ddt(T)  
      + fvm::div(phi, T)
      - fvm::laplacian(kappaEff, T)
    );

    TEqn.relax();
    TEqn.solve();

  //  h=thermo.Cp()*T;     //<--------this is enthalpy calculation!

  //  thermo.correct();

  //  rho=thermo.rho();
  //  nu=thermo.mu()/rho; 


createFields.H

PHP Code:


Info<< "Reading field p\n" << endl;
volScalarField p
(
    IOobject
    (
        "p",
        runTime.timeName(),
        mesh,
        IOobject::MUST_READ,
        IOobject::AUTO_WRITE
    ),
    mesh
);

Info<< "Reading field U\n" << endl;
volVectorField U
(
    IOobject
    (
        "U",
        runTime.timeName(),
        mesh,
        IOobject::MUST_READ,
        IOobject::AUTO_WRITE
    ),
    mesh
);

//add Temprature field and
Info<< "Reading field T\n" << endl;           
    volScalarField T
    (
        IOobject
        (
            "T",
            runTime.timeName(),
            mesh,
            IOobject::MUST_READ,
            IOobject::AUTO_WRITE
        ),
        mesh
    );




    Info<< "Reading field kappat\n" << endl;             
    volScalarField kappat                                                     
    (
        IOobject
        (
            "kappat",
            runTime.timeName(),
            mesh,
            IOobject::MUST_READ,
            IOobject::AUTO_WRITE
        ),
        mesh
    );


IOdictionary transportProperties
(
    IOobject
    (
        "transportProperties",
        runTime.constant(),
        mesh,
        IOobject::MUST_READ_IF_MODIFIED,
        IOobject::NO_WRITE
    )
);
dimensionedScalar nu
(
    "nu",
    dimViscosity,
    transportProperties.lookup("nu")
);

dimensionedScalar kappa
(
    transportProperties.lookup("kappa")
);

dimensionedScalar Pr
(
    transportProperties.lookup("Pr")
);

dimensionedScalar Prt
(
    transportProperties.lookup("Prt")
);


Info<< "Reading field gradT\n" << endl;
volScalarField gradT
(
IOobject
(
"gradT",
runTime.timeName(),
mesh,
IOobject::MUST_READ,
IOobject::AUTO_WRITE
),
mesh,
dimensionedScalar
(
"gradT",
kappa.dimensions()/dimLength,
0
)

);

#include "createPhi.H"


label pRefCell = 0;
scalar pRefValue = 0.0;
setRefCell(p, pimple.dict(), pRefCell, pRefValue);
mesh.setFluxRequired(p.name());


singlePhaseTransportModel laminarTransport(U, phi);

autoPtr<incompressible::turbulenceModel> turbulence
(
    incompressible::turbulenceModel::New(U, phi, laminarTransport)
);

#include "createMRF.H" 


please check it and if there is any mistake please correct me

thank you so much.

Srv