[MrFEA]

Hi Folks

I'm new to CFX. I'mtrying to simulate pressue inside a chamber connected to a vacuum pump. I have one intake with as wall (valve closed) and the other as outlet with mass flow. Inside is Air (ideal gas). Initial conditions of pressure is zero (relative to ambient 760 Torr).

The problem is to write boundary conditions of the outlet as the flow is a function of the pressure. I'm using a very simple equation using volumeAve(Pressure)@chamber X constant as test but flow is zero and the pressure doesn't drop. With a constant out flow it works fine.

Any ideas? Thx