[Maggakahn]

Hello fellow CFDers, I am quite new to FLUENT so any help would be greatly appreciated.

Problem description:
I want to study the classic Taylor-Couette problem consisting of an annular fluid domain encased by two concentric cylinders, where the inner most cylinder is rotating while the outer most cylinder is stationary. See the attached image for reference Taylor_vortecies.png.

As i want to study this problem using a 2D cross section of the concentric cylinders (z-r plane in the attatched image), I have encountered a problem with the boundary conditions for the rotating wall. I can not seem to find a way to give the rotating wall a speed in the theta (see attatch for ref) direction, i.e the normal direction of the crossectional 2D plane.

I have tried to use the Axissymmetric option in FLUENT, but since the axis of rotations placement differs from the rotational wall placement. For example if you had a 100mm inner cylinder, the axis of rotation would lie in the middle of that cylinder, while the rotational wall would be the wall of that cylinder. FLUENT does not seem to like if this is the case. For 2D pipe flows this is not a problem since the axis of rotation is in the middle of the pipe.

Thank you very much for reading. Any help is greatly appreciated!
Best regards,
Magnus