Hello. I am attempting to simulate the lift on a spinning cylinder using sliding mesh techniques. I create a first circular face for the cylinder, then a second circular face just slightly larger for interfaces and third circular face for a control area. I subtract the first face from the second face so that the cylinder is treated as a wall, and then subtract but retain the second cylinder from the third cylinder so that i can be left with two edges for interfaces. However when i do this the cylinder inside is created as a face again and two circular edges where the cylinder wall is meant to be are created. And i have tried a number of different ways of trying to alleviate this problem and get the cylinder moving in fluent, but even by applying a moving mesh to the fluid between the cylinder and interfaces the cylinder will not spin. Can anyone give any help on this. Thanks.

Why not mesh it like a stationary problem. Then in Fluent prescibe a moving wall with the axis of rotation being the cylinder axis. Doing it that way, there is no need for moving mesh or interfaces.