Ansys Fluent dynamic mesh problem

Fluid dynamics simulation should be created using dynamic meshing capabilities of Ansys Fluent. See attached image to get acquainted with the nature of the problem. A mechanism consists of stationary and moving parts. Moving part has sliding valves that move down to create closed chamber with inlet of stationary part. High pressure gas coming out the pressure inlet fill the space between inlet and valve and exert force on valve face. This force moves the moving part in -X direction. As valve moves farther from the inlet next valve slides down to create another closed chamber and so on. The process is cyclic. Further details will be given later.