Very Urgent Please help.

Nano Fluent

I'm an undergraduate student studying Fluent tutorial now. If you could give me a little help, it would be very grateful to me. ^^

There is a hexahedron chamber. It has three holes, two is small and one is larger. With these holes, make the chamber to be vacuummed.

From atmospheric pressure to 5Pa, use two small holes, and to vacuum, use a larger hole.

The problem here, if the pressure leads to 5Pa, FLUENT has to be stopped at that point, and switch the condition(from small holes to larger one) it should be reIterationed.

So, I made every effort to find that function in FLUENT, but I could not find any.

Is Everyone know about that?

It would be very thank you ...

The other one is...

The way(or equation) to measure a flux of the already known size of hexahedron.