supersonic flow at inlet and subsonic flow at outlet
 

Plz help me
i m working on supersonic flow

initial conditions

Mach no.1.5
inlet condition velocity and total pressure -supersonic flow
outlet condition-subsonic flow
i m getting problem is slover

mach no. is going very high then crash it

plz help me whatever condition is required for this type of problem.

Try very small physical time steps to get things started. If that does not work try local time scale factor. Once things are starting to converge go back to physical time scale.

supersonic flow at inlet and subsonic flow at outlet
 

thank you very much Glenn Horrocks,


i tried but still i m getting problem i mention about the boundary conditions and error
--------------------------------------------------------------------+
| ERROR #001100279 has occurred in subroutine ErrAction. |
| Message: |
| Floating point exception: Overflow |
| |
| |
| |
| |
| |
+--------------------------------------------------------------------+

+--------------------------------------------------------------------+
| ERROR #001100279 has occurred in subroutine ErrAction. |
| Message: |
| Stopped in routine FPX: C_FPX_HANDLER |
| |
| |
| |
| |
| |
+--------------------------------------------------------------------+

+--------------------------------------------------------------------+
| An error has occurred in cfx5solve: |
| |
| The ANSYS CFX solver exited with return code 1. No results file |
| has been created. |
+--------------------------------------------------------------------+

End of solution stage.

+--------------------------------------------------------------------+
| The following user files have been saved in the directory |
| F:\run\plasam_101_010: |
| |
| mon |
+--------------------------------------------------------------------+


This run of the ANSYS CFX Solver has finished.

1. Diameter: 1m
2. Mach no.:1.5
3.temp: 1300k
4.Velocity at inlet:1053m/s(cal from mach no.)
5. at outlet condition: mass flow rate:224.3
plz tell me the process its very urgent

plz help me

hi!! I was once doing a simulation of a supersonic nozzle with argon. it crashed always until I switched the heat transfer option to ''total energy''. in fact, the help says that it is reccommended for any flow with Mach number higher tan 0.3