[samufluent]

Hi everyone,
I am doing a simulation about a Taylor-Couette cylinder (coaxial tube cylinder) by using Ansys Fluent 2019. The system consists about a plain (section in 2D of the Taylor-Couette cylinder) in which pure water flows from the bottom to the top. The internal cylinder (wall in 2D) rotates and the external one is fixed. My purpose is to calculate the absorbed power at different rotation speeds of internal cylinder.
I would like to ask two questions:
1) What is the best method for turbulence of my system? I know that the k-epslon is not adequate for systems in which there are rotating components,
2) How can I understand in a system about this if the flow is laminar or turbulent? I found the specific Reynold's number for this system, but i have not found a boundary criteria (for example Re>2100 for flow in a tube).
Thank you