[KTG]

Hey all,


I am trying to come up with a way to have jump cyclic boundary condition with a linear change in the jump. I have a box with periodic sides, and I want to impose linear changes in the jump pressure at the bounday on two of the sides so that the (average or approximate) pressure gradient in the domain is at some angle to faces.



First question: Is there no way to do this with #codestream? I can't seem to modify just the

jump uniform 1;

Second question: Can anyone explain to me how this is calculated? I ran a test case for a uniform jump, and can see that I am getting the desired result, but am not sure how it actually works in terms of the FVM.



Third question: Given that I will probably have to write a new boundary condition from scratch and don't really konw C++ very well at all, can someone tell me what line to modify in jumpCyclicFvPatchField.C? I think it is the first half of the if statement here:

template<class Type>
void Foam::jumpCyclicFvPatchField<Type>::updateInterfaceMatrix
(
    Field<Type>& result,
    const bool add,
    const Field<Type>& psiInternal,
    const scalarField& coeffs,
    const Pstream::commsTypes
) const
{
    Field<Type> pnf(this->size());

    const labelUList& nbrFaceCells =
        this->cyclicPatch().neighbFvPatch().faceCells();

    // only apply jump to original field
    if (&psiInternal == &this->primitiveField())
    {
        Field<Type> jf(this->jump());

        if (!this->cyclicPatch().owner())
        {
            jf *= -1.0;
        }

        forAll(*this, facei)
        {
            pnf[facei] = psiInternal[nbrFaceCells[facei]] - jf[facei];
        }
    }
    else
    {
        forAll(*this, facei)
        {
            pnf[facei] = psiInternal[nbrFaceCells[facei]];
        }
    }

but I am not sure what psiInternal is? It would suffice for me to just be able to make a simple hard-coded calculation based on the coordinates of facei (baby steps)....


Thanks