foam-extend4.1-coherent-io/applications/solvers/heatTransfer/buoyantBoussinesqSimpleFoam/pEqn.H

{
    volScalarField rUA("rUA", 1.0/UEqn().A());
    surfaceScalarField rUAf("(1|A(U))", fvc::interpolate(rUA));

    U = rUA*UEqn().H();
    UEqn.clear();

    phi = fvc::interpolate(U) & mesh.Sf();
    adjustPhi(phi, U, p);

    surfaceScalarField buoyancyPhi =
        rUAf*fvc::interpolate(rhok)*(g & mesh.Sf());
    phi += buoyancyPhi;

    while (simple.correctNonOrthogonal())
    {
        fvScalarMatrix pEqn
        (
            fvm::laplacian(rUAf, p) == fvc::div(phi)
        );

        pEqn.setReference(pRefCell, pRefValue);

        pEqn.solve();

        if (simple.finalNonOrthogonalIter())
        {
            // Calculate the conservative fluxes
            phi -= pEqn.flux();

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

            // Correct the momentum source with the pressure gradient flux
            // calculated from the relaxed pressure
            U += rUA*fvc::reconstruct((buoyancyPhi - pEqn.flux())/rUAf);
            U.correctBoundaryConditions();
        }
    }

    #include "continuityErrs.H"
}