Squeeze Film

Duc

Dear Fluent experts,

I have been trying to model this problem without much luck, I believe I was looking at the wrong way. The schematic of the problem can be found in the link below:

http://www.geocities.com/ducums_2000/Squeeze.jpg

I tried to model the air gap between the 2 surfaces with a rectangular grid. The upper and lower boundaries being WALL and the left and right as PRESSURE OULET (1 bar). A VELOCITY UDF was applied to the UPPER WALL to describe the oscillating motion. Theory states that at high frequency oscillation (>1.5kHz) the pressure of the film rises above ambient. The solver was defined as UNSTEADY IMPLICIT and air as the working fluid. From results (3 cycles), I believe the model is wrong as no rise in pressure were seen.

I am using FLUENT5.5 without the dynamic mesh feature. Does anyone know of any approach to model this problem.

Your help and guidance are deeply appreciated.

Many thanks and regards,

Duc