[Java12]

Hey y'all, I've got a project for my compressible aerodynamics class where I have to simulate 12 different flows each for a converging-diverging and converging supersonic nozzles based on given inlet stagnation and outlet static pressures from some experiments my professor did a while ago.
For the simulations with low pressure ratios, I've been having issues where the solution starts really diverging, and get some fairly unrealistic results (e.g. considering NC State still exists, I can assume Mach 311 flow did not occur).


It's a 2D axisymmetric inviscid density-based flow simulation with ideal-gas air (default material properties) with the energy equation, all other models disabled. Inlet face is set as a pressure-inlet zone set so that both gauge and suspersonic gauge pressure are the given inlet pressure for a state, and the outlet face is set as a pressure-outlet zone with the gauge pressure set to the given outlet pressure as a static pressure. Any ideas on either making it behave more nicely or at least limit how unrealistic it gets?


The states I'm having the most trouble with:
Stagnation temperature T0 = 295 (Degree K)
Converging Nozzle
Stagnation Pressure at Inlet, P0 = 29.21786 (psi, absolute)
Static Pressure at Outlet, Pstatic,out = 29.21787 (psi, absolute)
Converging-Diverging Nozzle
Stagnation Pressure at Inlet, P0 = 29.56062 (psi, absolute)
Static Pressure at Outlet, Pstatic,out = 29.56593 (psi, absolute)


Thanks!