Rotating chamber

DS

I am modeling a flow through a rotating chamber of cylindrical shape. The axis of rotation is perpendicular to the direction of the rotating chamber. The side and the top views of the 3D geometry are shown in the figures. The asterix (*) represent a liquid outlet, which is located on the side of the chamber. The liquid inlet BC is velocity inlet (uniform velocity) and the outlet BC is outflow. A rotating reference frame is used.

Side view

axis of rotation (II), X interior

II

II=================

II=*XXXXXXXXXXXX=<--liquid inlet

II=================

II

Top view

===================

II=XXXXXXXXXXXXX=<--liquid inlet

==*================

I have the folloving questions for CFD guys: 1. How to calculate frictional and static pressure drop(consequence of centrifugal force field) separately? (I am able to determine frictional pressure drop experimentaly and I would like to compare to CFD results.) 2. When I use outflow BC I get convergence and solution easily. But that is not the case with a pressure-outlet BC (backflow). Why? 3. I tried to use 2D geometry to reduce computational time and I also have problems with convergence and backflow (even with outflow BC)

Simulation is transient, flow is laminar. If more details are needed, please let me know.

I will be grateful for any answer. David