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

PtrList<fvVectorMatrix> UEqns(fluid.phases().size());
autoPtr<multiphaseSystem::dragCoeffFields> dragCoeffs(fluid.dragCoeffs());

int phasei = 0;
forAllIter(PtrDictionary<phaseModel>, fluid.phases(), iter)
{
    phaseModel& phase = iter();
    const volScalarField& alpha = phase;
    volVectorField& U = phase.U();

    volScalarField nuEff(sgsModel->nut() + iter().nu());

    UEqns.set
    (
        phasei,
        new fvVectorMatrix
        (
            (scalar(1) + fluid.Cvm(phase)/phase.rho())*
            (
                fvm::ddt(alpha, U)
              + fvm::div(phase.phiAlpha(), U)
              - fvm::Sp(fvc::ddt(alpha) + fvc::div(phase.phiAlpha()), U)
            )
          - fvm::laplacian(alpha*nuEff, U)
          - fvc::div
            (
                alpha*(nuEff*dev(T(fvc::grad(U))) /*- ((2.0/3.0)*I)*k*/),
                "div(Rc)"
            )
         ==
          - fvm::Sp(fluid.dragCoeff(phase, dragCoeffs())/phase.rho(), U)
        //- (alpha*phase.rho())*fluid.lift(phase)
          + (alpha/phase.rho())*fluid.Svm(phase)
          - fvm::Sp
            (
                slamDampCoeff
               *max
                (
                    mag(U.dimensionedInternalField()) - maxSlamVelocity,
                    dimensionedScalar("U0", dimVelocity, 0)
                )
               /pow(mesh.V(), 1.0/3.0),
                U
            )
        )
    );
    mrfZones.addCoriolis(alpha, UEqns[phasei]);
    UEqns[phasei].relax();

    phasei++;
}