Boundary condition for propeller and flap

Ness

Hi everyone!

I need to model a propeller but I am not sure about the best way of doing it. The flow is 3D, but I have thought dealing it as a plane circle with fan_inlet as boundary condition. Do you think it is a good way? Maybe is better to make a short cylinder and set velocity inlet in a one base and fan_outlet at the opposite one... don´t know.

and, what do I need to set a wall like a flap able to move? Set it in the boundary conditions? Dynamic mesh? If so, does the mesh stay "stuck" along the boundary? what if the resultant mesh has a high value of skewness?

I hope you answer me, I figure it is not a very advanced or strange question. Just a beginner's one.

Thanks in advance!