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-   -   Initalization fails with Operation Pressure = 0 Pa (https://www.cfd-online.com/Forums/fluent/38350-initalization-fails-operation-pressure-0-pa.html)

Tobias October 24, 2005 07:37

Initalization fails with Operation Pressure = 0 Pa
 
Hi, maybe anybody is able to help me. I simulate a transsonic, one stage compressor. The compressor breathes air at normal conditions (Total pressure is 101325 Pa). The initialization makes no problem if I choose the Operation Condition Pressure to 101325 Pa and gauge inlet pressure to zero Pa, but fails if I twist this pair (operation condition pressure zero Pa, gauge Pressure to 101325 Pa) Perhaps anybody knows soething about this problem, please write it down. Thanks Tobias.

Ralf Schmidt October 29, 2005 13:45

Re: Initalization fails with Operation Pressure =
 
for the first iterations, fluent wants to calculate the density of the air... and this is not defined for zero pressure operating condition!!! (ideal gas law).

That makes Fluent to quit

Rajesh October 30, 2005 01:41

Re: Initalization fails with Operation Pressure =
 
What is the error message you are getting when you initialise the flow with zero operating pressure?


Tobias October 31, 2005 09:02

Re: Initalization fails with Operation Pressure =
 
Hello Rajesh. the point is that I did not recieve any error message, the pc "just" hanged up. This problem is now nearly two weeks ago. I simulated different operation points of my compressor until now by using operation pressure to 101325 Pa plus relative gauge pressure zero at inlet or plus relative gauge pressure grater than zero at outlet to decrease mass flow rate.

After this event I installed only the fluent programm part new. So now I am not sure if it was really a problem of fluent (I can not imagine this because it seems to be a basic key feature of a cfd programm !) or a problem of my system (maybe wrong memory deviece after first hang up).

So thanks for your interest.

Tobias


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