hello, I have a conceptual problem: I want to make an object rotating in a fluid. If a set a moving mesh problem (boundary condition/ fluid/ moving mesh/ rotation), the body will rotate togheter with the fluid. the tutorial guide about moving mesh does the same, but the body should not move with the fluid. It should be stopped and dipped in a rotating fluid. How to do?

you can try single rotating frame simulation. In this simulation, the object is held static and the liquid is simulated to rotate, relative to the object. Tutorial one single rotation fluid is available in Fluent's documentation.Good luck!

yes but in this way fluent considers the position of the body and the velocity of the fluid and composes the vectors. I want to underline he wake and the instationary problem. the single rotating frame simulation does not permit it. does it?

and moreover, people use moving mesh to simulate problems similar to mine. how do they do?