[crazzy.pirate43]

Dear Foamer,

I'm very happy to be a member of OpenFoam world. Nowadays, I'm trying to generate homogeneous turbulence at the inlet of channel flow which has fully developed UMean at inlet and a convection boundary layer for the pressure at the exit. The problem is that every run I get a problem with the pressure, it fluctuates from (+ve) to (-ve) between following time steps and therefore PMean is very small which means that in some time steps the pressure goes from low pressure at the inlet to high pressure at the outlet.

I attached 2 photos for the pressure behavior which affects on the behavior of the generated velocity fluctuation.
So could you please anyone can help me in this problem to know what may be the source of the error?

Thanks in advance for any help

Mohamed

pressure( ve).png

pressure(-ve).png


The attached photos for the pressure:
1- for (-ve) pressure values after 8 cycles.
2-for (+ve) pressure after 10 cycles.
(one cycle refers to that a particle of the flow completed the distance from the inlet to the exit)