[bou]

Dear,

I would like to compute on boundary faces (a patch) the convective flux so the sum of the simple product:

C*U.Sf,

where C is a volScalarField.

I have tried this:

double sum = 0;
forAll(mesh.boundaryMesh()[patch_bot], faceI){
    sum += U.boundaryField()[patch_bot][faceI] & mesh.boundaryMesh()[patch_bot][faceI].normal(pf);
}

and I don't know what to use as pointField argument "pf". Actually, I don't understand why I need to provide this argument.

Moreover is "U.boundaryField()[patch_bot][faceI]" a good way to get U on faceI?

Thank you,

Bou

[bou]

In case it could be usefull to others, here is the solution I found:

vectorField Sf(mesh.boundary()[patch_bot].Sf()); // normal face area vectors multiplied by the surface
vectorField UC(U.boundaryField()[patch_bot]*C); //much better results than // volVectorField UC("UC",U*C); 
        
Field<double> SUC = Sf & UC;

Regards,

Bou