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-   -   supersonic flow at inlet and subsonic flow at outlet (http://www.cfd-online.com/Forums/cfx/86041-supersonic-flow-inlet-subsonic-flow-outlet.html)

deep March 13, 2011 00:11

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.

ghorrocks March 13, 2011 06:46

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.

deep March 14, 2011 04:58

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

ingeniero_82 March 14, 2011 17:02

Quote:

Originally Posted by deep (Post 299147)
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.

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


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