[miguwhynot]

Hi everyone, I'm currently trying to simulate a simple air flow whose temperature and pressure change with the time.

The geometry is a cube, I have set the velocity-inlet in the top face and the pressure outlet at the bottom face. The only BC I have set are 4 m/s in the inlet and the pressure in the outlet (gravity also set), however I'm getting the:

Reverse flow message at x faces in pressure outlet. What I want it's a flow going at acertain velocity at a certain pressure.

How is this possible?

Edit: added photo of velocity contour at outlet, added photo of pressure outlet and operating conditions.