Hello, I wonder if some knows about a similar study that simulate the flow conditions in region below a rotating solid cylinder mounted vertically in a tank of water and the bottom wall of the tank. The gap between the lower tip of the cylinder and the bottom of the tank is about 25% of the cylinder diam. The dimensions of the tank (fiiled of water) and, off course, its lower bottom wall is infinitey compared to the cylinder.

I will highly appreciate your kind about aspects and physics of such a problem. Thanks

Interesting problem ...

I'd want to assume that the flow is axisymmetric to start.

I wonder about the effect of the rotation of the vertical wall of the cylinder on the flow. Angular momentum is being pumped into the surrounding fluid all the way up the side of the cylinder. So you need to decide how far up the cylinder your simulation has to reach - and what boundary conditions do you apply at the top.

Also, do Taylor vortices form? Normally these would form between two axisymmetric cylinders within certain rotating speeds - so this needs to be considered when you decide how far away the 'infinite' outer boundary is to be located.

You might want to look at Schlichting, Boundary Layer Theory, under the headings of "disk, rotating" and "disk, rotating in a housing" to try to visualize how the flow directly under your cylinder might look.

Good luck!