Supersonic Flow in UG/NX

[scottneh]

Hello, has anyone simulated supersonic flow in UG/NX? I have a fairly simple flat plate with a small protrusion. The simulation runs well up to mach 1 or so. when I try to run it at mach 1.08 it crashes. I talked with Maya tech support (they make the CFD package for UG) and they told me that the software isn't tailored for flows with "external shocks". The problem is that I am simulating flow through an arbitrary fluid volume which could be from the inside of a duct or inlet so from that perspective what's an "external shock"?

If anyone has done any simulation of supersonic flow in UG I would really appreciate any help you can offer. The up loaded picture is a close up of my model at Mach 1.

Thanks
Scott