I need an Ansys fluent expert

I am doing a 3D transient turbulent simulation in ansys fluent with a moving mesh. Basically the simulation is a slider that moves in an open tower up and down. To estimate the flow into the tower due to pressure drops due to the slider movement (similar to the piston effect at trains moving in a tunel) I need to simulate the motion with a moving mesh. The movement is a translation in just the z direction and it is a forced movement, as the silder is accelerated by a drive. I alredy tried a 3D simulation with an overset mesh, but I have some convergence problems. I would need advice and help on the simulation. The mesh and the dynamic mesh settings with the movement (via ttab) is alredy done. I have an very good overview of the project and the requirements, that I can provide as well as all of my previous work.