URGENT: How to set fixed volume rate in a air volume?
 

I have some problems with setting a fixed volume rate inside my computational domain, so extra BCs between two other pressure BC's.
I really don't know to which boundary condition (shown in green) it must be set. Can some one give me some advise about this problem? How can I solve this!

You can see I need to set a mass_flow_inlet or pressure inlet BC, and than the air must go through the rectangular shaps by fixed volume rate (can also be a fan), it will than be extracted by a pressure_outlet upstairs with a target mass_flow_rate. The rectangular shaps represent a heating source term to this volumes, which will heat up the air raising up.

The problem is in 3D and the meshing is done well.

PLEASE HELP:eek:

IS THERE ANYone who has an idea about this? My master thesis is really f* up now: Frustrating!