[Kaustatic]

Hi, I am trying to model a complicated multiphase process using CFX programmimg, to which I am very current. I have started working on it by making it a combination of two concentric cylinders in which one on top is a 30 mm wide , 20 mm long cylinder and the lower one starting from the end of the broader is 6 mm wide.

Keeping the narrow cylindrical region constant (stationary as outlet region), mesh displacement has been attempted on the broad cylinder on top. the top flat layer (30 mm wide) and the wall of the top layer has been subjected to a constant velocity. (The fluid is water at 25oC). I tried to set up a transient by trying to displace the top mesh by 5 mm following the CFX tutorial on fluid interaction and mesh deformation. A direct application showed only the initial flow state and the final flow state(right at the first timestep) and the rest of the time steps the mesh died out.

I tried to right expressions for the displacement, by multiplying a given velocity with the timestep and applied it to the top surface and the side qwall of top cylinder. but now, no movement at all. Help!!