openfoam/applications/solvers/multiphase/multiphaseEulerFoam/pEqn.H

{
    // rho1 = rho10 + psi1*p_rgh;
    // rho2 = rho20 + psi2*p_rgh;

    // tmp<fvScalarMatrix> pEqnComp1;
    // tmp<fvScalarMatrix> pEqnComp2;

    // //if (transonic)
    // //{
    // //}
    // //else
    // {
    //     surfaceScalarField phid1("phid1", fvc::interpolate(psi1)*phi1);
    //     surfaceScalarField phid2("phid2", fvc::interpolate(psi2)*phi2);

    //     pEqnComp1 =
    //         fvc::ddt(rho1) + psi1*correction(fvm::ddt(p_rgh))
    //       + fvc::div(phid1, p_rgh)
    //       - fvc::Sp(fvc::div(phid1), p_rgh);

    //     pEqnComp2 =
    //         fvc::ddt(rho2) + psi2*correction(fvm::ddt(p_rgh))
    //       + fvc::div(phid2, p_rgh)
    //       - fvc::Sp(fvc::div(phid2), p_rgh);
    // }

    PtrList<surfaceScalarField> alphafs(fluid.phases().size());
    PtrList<volVectorField> HbyAs(fluid.phases().size());
    PtrList<surfaceScalarField> phiHbyAs(fluid.phases().size());
    PtrList<volScalarField> rAUs(fluid.phases().size());
    PtrList<surfaceScalarField> rAlphaAUfs(fluid.phases().size());

    phasei = 0;
    for (phaseModel& phase : fluid.phases())
    {
        MRF.makeAbsolute(phase.phi().oldTime());
        MRF.makeAbsolute(phase.phi());

        HbyAs.set(phasei, new volVectorField(phase.U()));
        phiHbyAs.set(phasei, new surfaceScalarField(1.0*phase.phi()));

        ++phasei;
    }

    surfaceScalarField phiHbyA
    (
        IOobject
        (
            "phiHbyA",
            runTime.timeName(),
            mesh,
            IOobject::NO_READ,
            IOobject::AUTO_WRITE,
            IOobject::REGISTER
        ),
        mesh,
        dimensionedScalar(dimVelocity*dimArea, Zero)
    );

    volScalarField rho("rho", fluid.rho());
    surfaceScalarField ghSnGradRho(ghf*fvc::snGrad(rho)*mesh.magSf());

    phasei = 0;
    for (phaseModel& phase : fluid.phases())
    {
        const volScalarField& alpha = phase;

        alphafs.set(phasei, fvc::interpolate(alpha).ptr());
        alphafs[phasei].rename("hmm" + alpha.name());

        volScalarField dragCoeffi
        (
            IOobject
            (
                "dragCoeffi",
                runTime.timeName(),
                mesh
            ),
            fluid.dragCoeff(phase, dragCoeffs())/phase.rho(),
            fvPatchFieldBase::zeroGradientType()
        );
        dragCoeffi.correctBoundaryConditions();

        rAUs.set(phasei, (1.0/(UEqns[phasei].A() + dragCoeffi)).ptr());
        rAlphaAUfs.set
        (
            phasei,
            (
                alphafs[phasei]
               /fvc::interpolate(UEqns[phasei].A() + dragCoeffi)
            ).ptr()
        );

        HbyAs[phasei] = rAUs[phasei]*UEqns[phasei].H();

        phiHbyAs[phasei] =
        (
            fvc::flux(HbyAs[phasei])
          + MRF.zeroFilter
            (
                rAlphaAUfs[phasei]*fvc::ddtCorr(phase.U(), phase.phi())
            )
        );
        MRF.makeRelative(phiHbyAs[phasei]);
        MRF.makeRelative(phase.phi().oldTime());
        MRF.makeRelative(phase.phi());

        phiHbyAs[phasei] +=
            rAlphaAUfs[phasei]
           *(
               fluid.surfaceTension(phase)*mesh.magSf()
             + (phase.rho() - fvc::interpolate(rho))*(g & mesh.Sf())
             - ghSnGradRho
            )/phase.rho();

        auto dmIter = fluid.dragModels().cbegin();
        auto dcIter = dragCoeffs().cbegin();

        for
        (
            ;
            dmIter.good() && dcIter.good();
            ++dmIter, ++dcIter
        )
        {
            const phaseModel *phase2Ptr = nullptr;

            if (&phase == &dmIter()->phase1())
            {
                phase2Ptr = &dmIter()->phase2();
            }
            else if (&phase == &dmIter()->phase2())
            {
                phase2Ptr = &dmIter()->phase1();
            }
            else
            {
                continue;
            }

            phiHbyAs[phasei] +=
                fvc::interpolate((*dcIter())/phase.rho())
               /fvc::interpolate(UEqns[phasei].A() + dragCoeffi)
               *phase2Ptr->phi();

            HbyAs[phasei] +=
                (1.0/phase.rho())*rAUs[phasei]*(*dcIter())
               *phase2Ptr->U();

            // Alternative flux-pressure consistent drag
            // but not momentum conservative
            //
            // HbyAs[phasei] += fvc::reconstruct
            // (
            //     fvc::interpolate
            //     (
            //         (1.0/phase.rho())*rAUs[phasei]*(*dcIter())
            //     )*phase2Ptr->phi()
            // );
        }

        phiHbyA += alphafs[phasei]*phiHbyAs[phasei];

        ++phasei;
    }

    surfaceScalarField rAUf
    (
        IOobject
        (
            "rAUf",
            runTime.timeName(),
            mesh
        ),
        mesh,
        dimensionedScalar(dimensionSet(-1, 3, 1, 0, 0), Zero)
    );

    phasei = 0;
    for (const phaseModel& phase : fluid.phases())
    {
        rAUf += mag(alphafs[phasei]*rAlphaAUfs[phasei])/phase.rho();

        ++phasei;
    }

    // Update the fixedFluxPressure BCs to ensure flux consistency
    {
        surfaceScalarField::Boundary phib(phi.boundaryField());
        phib = 0;
        phasei = 0;
        for (const phaseModel& phase : fluid.phases())
        {
            phib +=
                alphafs[phasei].boundaryField()
               *(mesh.Sf().boundaryField() & phase.U().boundaryField());

            ++phasei;
        }

        setSnGrad<fixedFluxPressureFvPatchScalarField>
        (
            p_rgh.boundaryFieldRef(),
            (
                phiHbyA.boundaryField() - MRF.relative(phib)
            )/(mesh.magSf().boundaryField()*rAUf.boundaryField())
        );
    }

    while (pimple.correctNonOrthogonal())
    {
        fvScalarMatrix pEqnIncomp
        (
            fvc::div(phiHbyA)
          - fvm::laplacian(rAUf, p_rgh)
        );

        pEqnIncomp.setReference(pRefCell, pRefValue);

        solve
        (
            // (
            //     (alpha1/rho1)*pEqnComp1()
            //   + (alpha2/rho2)*pEqnComp2()
            // ) +
            pEqnIncomp,
            p_rgh.select(pimple.finalInnerIter())
        );

        if (pimple.finalNonOrthogonalIter())
        {
            surfaceScalarField mSfGradp("mSfGradp", pEqnIncomp.flux()/rAUf);

            phasei = 0;
            phi = dimensionedScalar("phi", phi.dimensions(), Zero);

            for (phaseModel& phase : fluid.phases())
            {
                phase.phi() =
                    phiHbyAs[phasei]
                  + rAlphaAUfs[phasei]*mSfGradp/phase.rho();

                phi +=
                    alphafs[phasei]*phiHbyAs[phasei]
                  + mag(alphafs[phasei]*rAlphaAUfs[phasei])
                   *mSfGradp/phase.rho();

                ++phasei;
            }

            // dgdt =

            // (
            //     pos0(alpha2)*(pEqnComp2 & p)/rho2
            //   - pos0(alpha1)*(pEqnComp1 & p)/rho1
            // );

            p_rgh.relax();

            p = p_rgh + rho*gh;

            mSfGradp = pEqnIncomp.flux()/rAUf;

            U = dimensionedVector("U", dimVelocity, Zero);

            phasei = 0;
            for (phaseModel& phase : fluid.phases())
            {
                const volScalarField& alpha = phase;

                phase.U() =
                    HbyAs[phasei]
                  + fvc::reconstruct
                    (
                        rAlphaAUfs[phasei]
                       *(
                            (phase.rho() - fvc::interpolate(rho))
                           *(g & mesh.Sf())
                          - ghSnGradRho
                          + mSfGradp
                        )
                    )/phase.rho();

                //phase.U() = fvc::reconstruct(phase.phi());
                phase.U().correctBoundaryConditions();

                U += alpha*phase.U();

                ++phasei;
            }
        }
    }

    //p = max(p, pMin);

    #include "continuityErrs.H"

    // rho1 = rho10 + psi1*p_rgh;
    // rho2 = rho20 + psi2*p_rgh;

    // Dp1Dt = fvc::DDt(phi1, p_rgh);
    // Dp2Dt = fvc::DDt(phi2, p_rgh);
}