[jonbonraki]

i m working on a project to simulate the air flow in a room, the boundary conditions i have got, is a mass flow inlet and pressure outlet, when i start iterating the solution in fluent, i m getting an error saying reverse flow in pressure outlet *******...where as i cant see the same error while i dealt the boundary condition at outlet as outflow..if u need further details i may present to you in next post...and also my advisor told me to treat the outlet which is nothing but 8 slots together to design for outlet boundary condition as velocity outlet.which is not possible to specify since we have only pressure outlet and out flow ofr outlet condition... so i have two questions here..ur answers will be appreciated.

[Bionico]

Hi jonboraki,
1) it's quite usual finding Reverse Flow in your kind of system, don't worry.
Usually this warning starts to increase for some iterations... but after that it decreases and should go to zero.
To be sure that it will happen, you should put your boundaries (either inlet and above all outlet) far enough from the room: so you should create a long tube in order to let the flow to stabilize.

2) Fluent Manual suggests using pressure outlet rather than outflow, so go ahead!

Sorry for my bad english

Regards