Vacum in cfx
 

hi. guys

i need to do a cfx simulation, where the flow is inside a vacum.say for ex. air flowing into a low pressure vessel from the atmosphere.anybody have idea of how to do this simulation.any suggestions??. i tried to give the boundry condition of the vessel as opening. so i can give my desired low pressure. but it returns error. anybody have any suggestions to solve this problem please post a reply.

cheers raj