Variable outlet
 

Hi Frens, I have a problem where I need to simulate the back pressure variation when a flow is getting obstructed by a closing valve. Initially the outlet area is maximum and after 2.5 sec the outlet area is minimum using this I need to simulate the back pressure developed. Accordingly I ll regulate my inlet flow to maintain a constant back pressure. But initally I need to find what is the maximum back pressure i am getting with this outlet area variation.

How i can do this problem and what are the boundary conditions I need to impose over the model.

Regards Badri