[kamakura117]

Hello,

I am beginning the development of another solver, but I'm pretty amateur at C++. The solver I am writing requires a bit more detailed source term than is possible, currently, with fvOption. In this effect, I am just beginning my baby steps. I have scoured the forum for an avenue forward, but I'm having some problems.

I am starting with OpenFoam 2.3.1.

So, simply speaking, I create a new scalar field in createSolidFields.H:

PtrList<volScalarField> q(solidRegions.size());
...

forAll(solidRegions, i)
    {
     ....
        Info<< "    Add  source\n" << endl;
        q.set
        (
            i,
            new volScalarField
            (
                IOobject
                (
                    "q",
                    runTime.timeName(),
                    solidRegions[i],
                    IOobject::MUST_READ,
                    IOobject::NO_WRITE
                ),
                solidRegions[i]
            )
        );

Then I suspect, I could simply add this in solveSolid.H:

        ==
            fvOptions(rho, h)
            + q

But, I am returned with an exceptionally long compilation error, which looks to be associated with a miss-match in matrix/scalar notion for the solver. However, as defined, the "q" source term is a matrix and the solver loop beings with "tmp<fvScalarMatrix> hEqn" So, I am a bit confused.

Any guidance would be appreciated.

[ssss]

Are you sure that the dimensions of q are right?, maybe you should use fvc::div(q).

[kamakura117]

Thanks for the response.

The dimensions of "q" are J/kg. It should be a scalar value. I don't think that a divergence makes sense here, or am I misinterpreting the result of the operation?

[ssss]

So if q is a scalar value, then you shouldn't be reading it as an IOobject, you should read it from as a dimensioned scalar from the transportProperties and then create a volScalarField from it if you want.

I meant that q must have the correct dimensions, as I see you are introducing the source term in the energy equation and thus it must have [J]/([m^3][s]) dimensions if I've done the operations correctly.

[kamakura117]

Hello,

I need to multiply by the density; however, I am just taking the source term one step at a time. Currently, I can't compile, so implicitly the dimensions don't matter too much until it reads in the initial conditions.

The IOobject is necessary. The computation of "q" will be done with an external code and I want it to be read from a file where I am writing a dictionary for all of the volumes. For each volume, it is a scalar, it is not a vector.

For completeness, the compilation error that I receive is a lot of something like:

/solid/solveSolid.H:17:26: note:   cannot convert ‘q’ (type ‘Foam::PtrList<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> >’) to type ‘const Foam::zero&’
             ) - q

and

./solid/solveSolid.H:17:26: note:   cannot convert ‘q’ (type ‘Foam::PtrList<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> >’) to type ‘const Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> >&’
             ) - q

Thanks.

[ssss]

I think I might have an answer for your errors. Open the setRegionSolidFields.H file and add this line:

 const volScalarField& qRegionI = q[i];

Then modify the hEqn in the solveSolid.H file:

        tmp<fvScalarMatrix> hEqn
        (
            fvm::ddt(betav*rho, h)
          - (
               thermo.isotropic()
             ? fvm::laplacian(betav*thermo.alpha(), h, "laplacian(alpha,h)")
             : fvm::laplacian(betav*taniAlpha(), h, "laplacian(alpha,h)")
            )
          ==
            fvOptions(rho, h)
            +qRegionI
        );

The problem relies in the fact that you are creating an array of q objects, one for each of the solidRegions, so when you discreteza the hEqn, you must select the element of q which relies in the region you are solving. Hope it helps.

[kamakura117]

Excellent! I didn't even notice that header file, and that's exactly what was happening.

Cheers.