Pressure
 

Hi, I have a problem with the test I'm trying to simulate (a fire in a tunnel) with PHOENICS, since I don't understand how the CFD handles the pressure at the exit of my tunnel. The problem is: I have to assign a boundary condition at the entry and at the exit of my tunnel and I have these two coefficient to give:FIXP and FIXVAL. The questions are: 1) In PIL, what is the difference between FIXP and FIXVAL ? 2) How does PHOENICS use them ? 3) Wich one is correct ?

If someone can help me I'll appreciate. I'm here for other clarifications. Yours, Gabriel.