Custom a polyPatch/fvpatch possible
 

Dear Foamers,

I working on a project where I need to add a coustom patch to OpenFOAM. Meaning not just a boundary condition (-> fvPatchField) but also a custom underlying polyPatch/fvPatch. The functionality can be ybout the same as needed for a normal boundary condition (e.g. fixedValue).

My problem: When I build a custom polyPatch/fvPatch inheriting for example wallPolyPatch / wallFvPatch and configure the boundary-file appropriately my custom patch is used - everything looks fine in the beginning. Using icoFoam, the Ux, Uy, Uz equations are solved as expected. When entering the PISO block I always get a floating point exception in the following division:
volScalarField rUA = 1.0/UEqn.A();

Has anybody a hint what I might be missing? What patch type does a boundary condition as fixedValue use?

Any hints are appreciated! thanks in advance!
-Andreas