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Old   May 2, 2005, 11:31
Default Transient - Momentum Source
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stex_
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In this days I run some stationary problems in a module of heat exchanger at low Re appling a "Momentum Source" and "periodic" boundary condition for inlet-outlet.

Growing up the velocity we know that in this problems we have some non-stationary effect, so the question is: "Is it possible to define a momentum source in a "transient" simulation?"

In theory if you define a Mom.Source you specify a constant deltaP, but in a transient phenomena the delta P is variable!

In fact I tried and after some iterations the solver stopped due to very high Mach number (floatin point error)!!!

Maybe someome can help me to turn the problem...

THANKS.
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Old   May 2, 2005, 18:44
Default Re: Transient - Momentum Source
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Glenn Horrocks
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Hi,

Yes, it is possible to implement a transient source. I suspect your floating point error is caused by divergence in the simulation.

Regards, Glenn
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Old   May 4, 2005, 09:10
Default Re: Transient - Momentum Source
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stex_
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Ok, but I've tryed with both constant and time-dependent values of the Mom. Source (e.g. t*100) and everytime I got the same error. The mesh is ok, because with stationary run, I got good results.

How do I have to proceed?

Thanks
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