[DnyanMiri]

I want to simulate a simple suction process. There is a box, which is placed at the center on the floor. There is a inlet to this box on one side. I want to have air coming in to the box from the room through this inlet at a certain mass flow rate/ velocity.

There are two fluid (air) domains, one is room and other is box. As these are both fluid domains, the inlet face is considered as an interface. Is there any way I can control the mass flow rate/velocity through this surface?

Let me know if any other info is needed.
Thanks,
Dnyanesh