Model?
 

I am doing analysis of flow past a rotating cylinder with Reynolds number below 2000. What is the best suit model for this problem? Whether i should use laminar model or should go for any turbulent model?

For a stationary cylinder the flow is laminar at Re=2000. So unless the rotation of your cylinder is extremely fast (enough to trip turbulence) you should be using a laminar model. Note that it will be shedding vorticies so you will need a transient model.

can you please suggest me the better turbulent model in case the flow becomes turbulent. Now i am using sst model. Whether i should try any other model?

I should put this up as an FAQ:

Unless you have a clear reason not to, you should use SST. You have not stated a clear reason to not use SST - so you should use SST.

thank you...