set the Rv and Rs factors to the saturated values for cells which have no gas and no oil
the purpose of this is to get a more defined behaviour when doing the
gravity correction/upstream cell determination in the flux term.
I consider this to be just a kludge, so if anyone has a better idea of
what the composition for the non-existing gas and oil phases is,
please tell me. (note that generic compositional models do not exhibit
this issue because the composition of all fluids is always fully
defined because each component is assumed to dissolve in every phase.)
also be aware that this PR is independent of OPM/opm-simulators#845.
It's a known singular thing, and we just hope it does not bite us... I have some problem understanding why this should matter for the upstream determination, could you point to the code that is affected?
> note that generic compositional models do not exhibit
> this issue because the composition of all fluids is always fully
> defined because each component is assumed to dissolve in every phase
Is this true? If you use component fractions (that sum to one for a phase) they would have the same kind of singularity when a phase disappears? I guess that means you do not use such fractions?