Multi-Stage Compressor
 

Hey All,

There is a compressor which working in vacuum conditions. Also take N2 from 0.01 [mbar] (this is absolute pressure) and i want to model this in CFX.

My boundary conditions are;
inlet=0.01 mbar static pressure
outlet= 0.0125 kg/s
Pref= 0 [atm]

But pressure contours on CFX-Post i see negative pressure values about -2.5 [bar] this is physically not valid. Because environment is 0.01 [mbar] absolute pressure.

Does anyone have a suggestion for me?

Thanx

I assume you are running a compressible flow. I can't see how you would get negative absolute pressures as the density is undefined and therefore the solver would diverge. Are you sure you have your reference pressure set correctly?

Glenn