[noorsalehi]

Hi All,
I have tried to simulate an inviscid supersonic diffuser in Fluent. The inlet boundary conditions are: mach number=3 , Total Pressure is 70000 pa & Total Temperature=300 K. I expect to have a normal shock in the throat or in the beginning of the diverging zone of the diffuser. Therefore the outlet flow regime must be subsonic.
As an initial solution, I have put “outlet vent” boundary condition at the outlet with the coefficient of 0.9. The solution has converged and the normal shock has been stabilized in the diverging zone of the diffuser. At the following of the run, when I change the outlet condition to “pressure-outlet”, the converging trend of the solution will not continue.
I have tested this procedure with various back pressures at the outlet, but results are the same as above.
Would you please help me solving this problem?

[majid pourdian]

Originally Posted by noorsalehi

Hi All,
I have tried to simulate an inviscid supersonic diffuser in Fluent. The inlet boundary conditions are: mach number=3 , Total Pressure is 70000 pa & Total Temperature=300 K. I expect to have a normal shock in the throat or in the beginning of the diverging zone of the diffuser. Therefore the outlet flow regime must be subsonic.
As an initial solution, I have put “outlet vent” boundary condition at the outlet with the coefficient of 0.9. The solution has converged and the normal shock has been stabilized in the diverging zone of the diffuser. At the following of the run, when I change the outlet condition to “pressure-outlet”, the converging trend of the solution will not continue.
I have tested this procedure with various back pressures at the outlet, but results are the same as above.
Would you please help me solving this problem?

i have same problem