[AmreD]

Hello,


I'm running a steady-state simulation for a centrifugal compressor using air. It's an openly available test case, the "MTU Radiver" compressor. The issue is two-fold, I'm getting higher pressure ratios than experimental values by about 0.5 even at different performance points (speeds/mass flows). So, boundary conditions that should produce a total pressure ratio of 2.5 according to the experimental results actually result in a 3.0 ratio. The second issue is that the total-total isentropic efficiency is around 88% when it should be around 75%.



I'm using the SST turbulence model. The boundary conditions are total pressure and total temperature at the inlet and mass flow rate at the outlet. The interfaces between the rotor and inlet/outlet are all frozen rotor interfaces. The simulations seem to be converging well, imbalances are within 1%, and there's no oscillation or anything. But, the final results are clearly off. I've attached the outfile, a screenshot of the run monitors, and the turbo macro "Gas Compressor Performance" report results.


Please let me know if any more info is required and thank you!