how to set bc in a pump simulation
 

Hi, I'm new to FLUENT and working on a simulation of fluid flow in valve-less pump.
The pump consist of one chamber and two lets(big inlet and small outlet).
There's one diaphragm which periodically push and pull.
When it push, large quantity of water come into the chamber from inlet and little water come out from the outlet;
when it pull, large quantity of water come out from the outlet and little water come in from the inlet.
What my problem is I dont know how to set the bc. I tried to set the diaphragm as the periodic and inlet&outlet as the shadow, but it seemed wrong.
Has anyone who worked on this or know how to solve that? Thanks!

itsqi7