Boundary conditions for volume increase through mesh deformation
 

Hey,

I'm trying to set up a problem in Fluent that essentially consists of a moving wall, mesh deformation, and thus a volume change causing under-pressure, and flow into the domain.

I'm confused about the boundary conditions I should choose for the inlet. Please have a look at the attached drawing for more details.

My idea is to use a pressure-inlet and prescribe 0 gauge pressure (since I think there is ambient pressure at the open boundary). Then the volume change in the left part should cause an under-pressure, and the flow (red arrows) should occur.

Are my ideas right? Any comments are welcome!