Two pressure outlets, no inlet???
 

Is it possible to have a situation where you define two pressure outlets but no inlets?

For example, I have a tube filled with stationary fluid open at both ends. Initially there is no flow.

I then compress the tube in the middle so that flow exits the ends of the tube. I then release the tube so that there is flow back into the tube.

Sounds like a simple model but the BC are killing me!

Help please :)