[jherb]

Hello,

I am trying to access the species thermo functions, especially HE and Cp/Cv, from within a boundary condition for chtMultiRegionFoam.

The starting point is this boundary condition implemented in OpenFOAM-8: https://github.com/OpenFOAM/OpenFOAM...hScalarField.C

Depending, on which side of the wall the solver is, there is either a fluid or a solid thermo model.

For the fluid side, I was able to access the methods using this (pseudo) code:

    if (mesh.foundObject<rhoReactionThermo>(basicThermo::dictName))
    {
        const rhoReactionThermo& nbrThermo =
            mesh.lookupObject<rhoReactionThermo>(basicThermo::dictName);

        const basicSpecieMixture& composition = nbrThermo.composition();
        const PtrList<volScalarField>& Y = composition.Y();

//        Info<<"Y.size: " << Y.size() << endl;

        forAll(TList, faceI) {
            scalar he = 0;
            scalar Cpv = 0;
            if (Y.size() > 0) {
                forAll(Y, componentI) {
                    scalar Yi = Y[componentI].boundaryField()[samplePatchi][faceI];
                    he += Yi*composition.HE(
                        componentI, nbrPPatch[faceI], TList[faceI]
                    );
                    Cpv += Yi*composition.Cp(
                        componentI, nbrPPatch[faceI], TList[faceI]
                    );
                }
            }
            else
            {
                scalar Yi = 1;
                he += Yi*composition.HE(
                    0, nbrPPatch[faceI], TList[faceI]
                );
                Cpv += Yi*composition.Cp(
                    0, nbrPPatch[faceI], TList[faceI]
                );
            }
    }

One thing, I do not really understand is the case, where I have a pureMixture and then, Y() returns a list of length zero. Nevertheless, if I use the index 0 for the access of the methods, it seems to work. Why?

On the solid side, I was not able to get hold on any "composition". I tried something like this:

        const solidThermo& nbrThermo = 
            nbrMesh.lookupObject<solidThermo>(basicThermo::dictName);

but solidThermo does not have a composition() method. Looking in the source code, there is a class heSolidThermo using the methods HE and Cp, but I was not able to use it, because I did not find correct template arguments to create a reference and assigning something inside the objectRegistry to this reference.

Is there a way to access this compositon/mixture methods of a solid?

Thank you for any help
Joachim

[clapointe]

I've been working through similar issues recently, I think. I'm not sure about accessing composition/etc for solidThermo, but what I've done is use a solid reaction thermo... you could use it without reactions, and it should provide a means to use a multi-component (homogenous) mixture if desired. Then you can access using something like :

solidReactionThermo& solidThermo = solidThermos[i];
basicSpecieMixture& composition = solidThermo.composition();
PtrList<volScalarField>& Ys = composition.Y();

This assumes that you open to using a version different from OpenFOAM 8 (for which the solid reactions are in some phase of restructuring). I suppose another option is to port solidReactionThermo from 7 to 8...

Caelan

[jherb]

Thank you for your answer. Unfortunately, I would like to do this in OpenFOAM-8. And solidReactionThermo was completely removed in this version.