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-   -   Guage vs. Absolute pressures in Fluent. (https://www.cfd-online.com/Forums/fluent/35471-guage-vs-absolute-pressures-fluent.html)

Riaan January 14, 2005 14:40

Guage vs. Absolute pressures in Fluent.
 
Hi guys,

I am running 2 identical cases, except that one uses guage pressures on the B.C (operation condition = 101352Pa) and the other uses absolute pressures (operating condition = 0Pa) on the B.C.

When I use guage pressures, the case converges to 10e-4, but when I use the absolute pressures to 10e-2 and levels off.

In my case, I am using a 1st order segregated solver, laminar, PISO, with pressure far-field and pressure inlet and exit B.C. My freestream Ma number is above 0.1, so the Fluent manual states that I should rather use absolute pressures.

Has anyone come across something similar?

Thanks, Riaan


Riaan January 21, 2005 14:22

Re: Guage vs. Absolute pressures in Fluent.
 
Quick Update: I have managed to do a couple more cases - and it still appears that if I use guage pressures I get much better convergence than absolute pressures.....


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