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Kevin August 1, 2005 21:50

Negative Pressure
 
In calculating the converging-diverging supersonic nozzle with the FINE/Turbo, the NEGATIVE pressure or density in domain comes so often during iterations finally ending up with a crash. Total pressure and temperature with flow angles were given at the inlet boundary, and static pressure was given in the outlet boundary when subsonic. The CFL number has been lowered up to 0.01 but in no use. Anyone with a better idea, please ?

Just a guess August 5, 2005 12:20

Re: Negative Pressure
 
Are you sure of your boundary conditions, i.e. that the static pressure at outlet is lower than the total pressure at inlet ?

Kevin August 10, 2005 04:54

Re: Negative Pressure
 
Of course. 7 bar pressure at inlet and atmosphere at exit are applied to the impulse turbine stage.

sffsa August 12, 2005 03:27

Re: Negative Pressure
 
hfhdfd

ing September 21, 2005 18:51

Re: Negative Pressure
 
If you are using the fine turbo upwind scheme this isn't surprising. There are major errors in the implementation.

rupesh January 9, 2006 01:22

Re: Negative Pressure
 
hi

Just check the operating pressure what you given . if u specified Pr. there just make it zero. while definig inlet Pr. make gauge pr. as 101325 and defaine ur inlet pr. and the outlet pr. must be less than inlet pr.


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