[trailer]

Hello to all,

I would like to know how to add a mass source term to compressibleInterFoam and a clarification on fvOptions code syntax.

In my simulation phase1 is water and phase2 is air.

Since we are using the mass conservation equation to write the pressure correction equation, the mass source should be placed there (is this correct?).

In pEqn.H file we have from line 26 to 95

   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))
            );
    }

Where the fvOptions is available on line 41 and 58 for transonic flow and in line 79 and 90 for the remainder.

I would like to know the following:
How can I put a source term there?

In my fvOptions dictionary I have:

massSource
{
    type            scalarCodedSource;
    selectionMode   all;
    fields          (?thermo:rho.water?);

    // Name of the coded source
    name            sourceTime;

But this does not change my simulation results... ( I am using an equation of state with constant density)


Additionally, can anyone clarify the entries on the fvOptions code syntax, e.g.,

fvOptions(alpha1, mixture.thermo1().rho())&rho1)

Or in the UEqn.H

fvOptions(rho, U)

what does (rho,U) mean? U is the field where the source is being implemented, but why is rho being passes as an argument?

[CorbinMG]

Hi trailer,

Did you ever figure out how to add the mass source term to the compressibleInterFoam solver? I am trying to do a similar thing but I am struggling to figure out the formulation of the p_rghEqnComp1 and p_rghEqnComp2 in pEqn.H.

Best regards,
Corbin