CFD Online Discussion Forums - rotating porous media in a general flow

Hi,

I want to perform a simulation of a flow through a rotating porous media in 3D . My geometry in simple :
-1: I have a cylinder which is porous and in which the flows rotate : I have simply define the appropriate locale coordinates and the axes of rotation ; As I want the flow inside to have a specific velocity :I used the fixed values with a tangential velocity ; this works fine as I have in my simulation the velocity vectors which are in the right direction and according the axis of rotation.
- 2 The problem is that this porous cylinder is in a 3D quadratic Control Volume in which the flow is flowing perpendicular to the axis of rotation in the cylinder.

I expected the main flow from the 3D quadratic Control Volume, to be swept along by the local current in the porous cylinder : But apparently not : it seems to be simply deviated by the porous cylinder and so this main flow is simply flowing around the cylinder and no pathlines passé through the cylinder : so the boundary of the cylinder is acting like a wall which deflects the main flow

What is wrong here ? thanks for any help.