[solene]

Hi everyone,

I am facing a problem with simulating a transient flow in fluent. At t=0, the cavity is filled with helium. Pint>Pext. During the simulation, there is a mass flow rate at the outlet (exit surface of the small cylinders you can see on the picture). The problem is the following: Pressure inside the cavity (as density and temperature) remains constant. In reality it should varies since the amount of helium in the cavity is going away from it. (there is neither a creation of matter inside the cavity nor an inlet)
Do you know what is the source of this problem?

Settings:
Transient, density-based solver
Energy on, Viscous k-epsilon realizable
Helium: density=ideal gas
Everything is considered as a wall except the exit surface of cylinders (pressure outlets)
Implicit and second order method