[amin144]

Dear Foamers,
I have read every posts about pressure driven flow but finally I need some one only tell me is it right my conclusion about pressure boundary condition in poiseuille flow, or not:

if we have a pressure driven flow and we don't know about velocity but we know pressure boundary condition,

we use velocity (U/0) in this form:
inlet :
type pressureInletVelocity
value uniform(0 0 0 ) ;
outlet:
type zerogradient

and pressure as below:

inlet:
type fixedValue;
value uniform 1; (we assume 1 is value of pressure at inlet)

outlet
type fixedValue;
value uniform 0;

And another queation, is this pressure value, real or divided by density?