[cfduser9]

I have created a gas distributor with high back pressure and a choked inlet distributing into a vacuum (the operating pressure is not quite zero, but very close).

Using the pressure-based solver, I have attempted to solve. The model always diverges. No matter how much I play with the under-relaxation factors, it simply won't converge.

Should I be using the density solver over the pressure solver? I am aware of the relative merits of each, but don't know what to do for this situation. The flow is slow near the inlet, but definitely compressible by the exit. It seems to fall between the two solvers, but maybe one is better than the other?

I should mention that the model is very complicated, as the distributor has many exits. A simpler model does converge using the pressure solver, but the real one does not.

Thanks!