[hessam]

Hello
I'm trying to simulate a rotating cylinder in a channel in fluent ( Re=100), but i have problem with choosing right model for it.
I choose k epsilon at first but the solution didn't converged in some meshes
I have same problem also in k omega model
Can you anyone help me?

[CeesH]

is the reynolds number based on the diameter of the cylinder or the channel? It may be that your flow is not turbulent, in which case you may prefer to go for the laminar model (with sufficient mesh resolution - the flow may still be complex). Why did you start with k-e?

[hessam]

Reynolds number is based on cylinder diameter.
I tried laminar model at first but the solution didn't converged in any meshes i tried and also i because of rotation of the cylinder,flow can't be laminar ( I asked from my master in university)

[Kirill-MIPT]

Try sst-kw, it combines k-w near the wall and k-e far from the wall

Sent from my Redmi Note 3 using CFD Online Forum mobile app

[sbaffini]

Your basic Re number is not turbulent (so laminar is ok), but you have vortex shedding (steady not ok, you need to go unsteady). Still, rotation of the cylinder can be characterized by an additional Re number (which you miss to provide). You can surely find some source online which gives you the range of Re and rotations for which the flow is laminar. But I think that steady is not an option here.