I tried to model a hypersonic (M=8) problem in COMSOL - a blunted wedge. I started to get probelms with a low stagnation velocity and results that strongly disagreed with other CFD codes. I was ultimately told by COMSOL tech support that the code can't do hypersonic flow - the available turbelence models cannot handly that regime:
"the available turbulence models in COMSOL in "hmnf" interface would not lead to accurate resolution of phenomenon occuring near wall in hypersonic regime, specifically shock-boundary layer interaction."
Has anyone had any success in the hypersonic regime with COMSOL? I think it's unfortunate it can't do these problems.