pEqn.H

{
    volScalarField rAU("rAU", 1.0/UEqn.A());

    surfaceScalarField rAUf("rAUf", fvc::interpolate(rAU));
    volVectorField HbyA(constrainHbyA(rAU*UEqn.H(), U, p_rgh));

    surfaceScalarField phiHbyA
    (
        "phiHbyA",
        fvc::flux(HbyA)
    );

    if (ddtCorr)
    {
        surfaceScalarField faceMaskOld
        (
            localMin<scalar>(mesh).interpolate(cellMask.oldTime())
        );
        phiHbyA +=
            MRF.zeroFilter
            (
                fvc::interpolate(rho*rAU)*faceMaskOld*fvc::ddtCorr(U, Uf)
            );
    }

    MRF.makeRelative(phiHbyA);

    surfaceScalarField phig
    (
        (
            mixture.surfaceTensionForce()
          - ghf*fvc::snGrad(rho)
        )*faceMask*rAUf*mesh.magSf()
    );

    phiHbyA += phig;

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

    tmp<fvScalarMatrix> p_rghEqnComp1;
    tmp<fvScalarMatrix> p_rghEqnComp2;

    if (pimple.transonic())
    {
        #include "rhofs.H"

        surfaceScalarField phid1("phid1", fvc::interpolate(psi1)*phi);
        surfaceScalarField phid2("phid2", fvc::interpolate(psi2)*phi);

        p_rghEqnComp1 =
            pos(alpha1)
           *(
                (
                    fvc::ddt(alpha1, rho1) + fvc::div(alphaPhi1*rho1f)
                  - (fvOptions(alpha1, mixture.thermo1().rho())&rho1)
                )/rho1
              - fvc::ddt(alpha1) - fvc::div(alphaPhi1)
              + (alpha1/rho1)
               *correction
                (
                    psi1*fvm::ddt(p_rgh)
                  + fvm::div(phid1, p_rgh) - fvm::Sp(fvc::div(phid1), p_rgh)
                )
            );
        p_rghEqnComp1.ref().relax();

        p_rghEqnComp2 =
            pos(alpha2)
           *(
               (
                   fvc::ddt(alpha2, rho2) + fvc::div(alphaPhi2*rho2f)
                 - (fvOptions(alpha2, mixture.thermo2().rho())&rho2)
               )/rho2
             - fvc::ddt(alpha2) - fvc::div(alphaPhi2)
             + (alpha2/rho2)
              *correction
               (
                   psi2*fvm::ddt(p_rgh)
                 + fvm::div(phid2, p_rgh) - fvm::Sp(fvc::div(phid2), p_rgh)
               )
           );
        p_rghEqnComp2.ref().relax();
    }
    else
    {
        #include "rhofs.H"

        p_rghEqnComp1 =
            pos(alpha1)
           *(
                (
                    fvc::ddt(alpha1, rho1) + fvc::div(alphaPhi1*rho1f)
                  - (fvOptions(alpha1, mixture.thermo1().rho())&rho1)
                )/rho1
              - fvc::ddt(alpha1) - fvc::div(alphaPhi1)
              + (alpha1*psi1/rho1)*correction(fvm::ddt(p_rgh))
            );

        p_rghEqnComp2 =
            pos(alpha2)
           *(
               (
                   fvc::ddt(alpha2, rho2) + fvc::div(alphaPhi2*rho2f)
                 - (fvOptions(alpha2, mixture.thermo2().rho())&rho2)
               )/rho2
             - fvc::ddt(alpha2) - fvc::div(alphaPhi2)
             + (alpha2*psi2/rho2)*correction(fvm::ddt(p_rgh))
            );
    }

    // Cache p_rgh prior to solve for density update
    volScalarField p_rgh_0(p_rgh);

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

        solve
        (
            p_rghEqnComp1() + p_rghEqnComp2() + p_rghEqnIncomp,
            mesh.solver(p_rgh.select(pimple.finalInnerIter()))
        );

        if (pimple.finalNonOrthogonalIter())
        {
            p = max(p_rgh + (alpha1*rho1 + alpha2*rho2)*gh, pMin);
            p_rgh = p - (alpha1*rho1 + alpha2*rho2)*gh;

            dgdt =
            (
                alpha1*(p_rghEqnComp2 & p_rgh)
              - alpha2*(p_rghEqnComp1 & p_rgh)
            );

            phi = phiHbyA + p_rghEqnIncomp.flux();

            U =
                cellMask*
                (
                    HbyA
                  + rAU*fvc::reconstruct((phig + p_rghEqnIncomp.flux())/rAUf)
                );

            U.correctBoundaryConditions();
            fvOptions.correct(U);
        }
    }

    {
        Uf = fvc::interpolate(U);
        surfaceVectorField n(mesh.Sf()/mesh.magSf());
        Uf += n*(fvc::absolute(phi, U)/mesh.magSf() - (n & Uf));
    }

    // Make the fluxes relative to the mesh motion
    fvc::makeRelative(phi, U);

    // Zero faces H-I for transport Eq after pEq
    phi *= faceMask;

    // Update densities from change in p_rgh
    mixture.thermo1().correctRho(psi1*(p_rgh - p_rgh_0));
    mixture.thermo2().correctRho(psi2*(p_rgh - p_rgh_0));

    rho = alpha1*rho1 + alpha2*rho2;

    // Correct p_rgh for consistency with p and the updated densities
    p_rgh = p - rho*gh;
    p_rgh.correctBoundaryConditions();

    K = 0.5*magSqr(U);
}