Compressible Flow through small gap

Andreas

Hello,

even though I studied previous posts regarding the modelling of compressible flows I still could not succeed. I model the flow that exits a chamber (2e5 Pa) via a small gap (height 0.5 mm and rectangular shape). Therefore I assumed a free jet flow modelling the ambient region with pressure outlets as BC. I also applied symmetry conditions. The inlet BC is: gauge total pressure: 2e5 Pa, initial sub.pressure:101325 Pa and for the pressure outlets 101325 Pa, respectively. Operating pressure is set to zero. Even though I am using coupled implicit solver I can only get sth. like convergence for time steps <1e-6. Does anyone has some ideas how to model compressible nozzle flows best ? Is CFX maybe more applicable for such problems? Thanks for the help,

Andreas