how does pressure inlet acts exactly?whats prosedure in subsonic?
 

I'm confused.I need to know how does pressure inlet boundary condition works in FLUENT.I've read user guide and help.but I'm not sure whats the algorithm behind pressure inlet BC.
my case is subsonic but compressible internal flow in a tube like shock tube.
does static pressure is read from internal field of domain (adjacent cells) or its calculated from isentropic relation?if latter how when Mach is un known?
if former then Mach is obtained from isentropic p relation?if so the pressure on patch and in adjacent will be the same then whats forces flow to be inflow?
whats the procedure?:confused:
thanks.

does any dear one knows to help me.i'm in an urgent situation.
Thanks.

can't anyone do any help?

how does totalPressure work?
(the summary of the question):confused:

there isn't any help?:(