volScalarField rAU(1.0/UEqn.A());
surfaceScalarField rhorAUf("rhorAUf", fvc::interpolate(rho*rAU));
volVectorField HbyA(constrainHbyA(rAU*UEqn.H(), U, p));
    surfaceScalarField phiHbyA
    (
        "phiHbyA",
        (
            fvc::flux(rho*HbyA)
          + rhorAUf*fvc::ddtCorr(rho, U, phi)
        )
    );


    MRF.makeRelative(fvc::interpolate(rho), phiHbyA);

//adjustPhi(phiHbyA, U, p);

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

// Non-orthogonal pressure corrector loop
while (piso.correctNonOrthogonal())
{
    // Pressure corrector

        fvScalarMatrix pEqn
        (
            fvm::ddt(psi, p)
          + fvc::div(phiHbyA)
          - fvm::laplacian(rhorAUf, p)
         ==
            parcels.Srho()
          + fvOptions(psi, p, rho.name())
        );


    //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();
fvOptions.correct(U);