Inertia Effects on Compressible Squeeze Films

Abstract

In this paper, the combined effects of compressibility and fluid inertia in a squeeze film are considered. The governing equations are derived using an integral method for a one-dimensional case, initially considering a combination of Couette and Poiseuille Flows. Numerical and experimental results are obtained for the case of a pure squeeze film between flat circular disks. Influence of the film geometry was examined by considering a cavity on the surface of one of the disks. The numerical solutions are obtained by use of the Crank-Nicholson method with Lax modification. Comparison of the numerical results for pressure in the film with the experimental results show good agreement. The inertia of the fluid is found to significantly influence the pressure waveform in the film by altering the phase of the pressure developed in the film with respect to the oscillating disk. It is shown that these phase changes lead to “resonances” in the mean bearing force. The results also show that the mean bearing force can be superambient or subambient depending on the squeeze number. Both the damping and the bearing force show a “jump” at a critical squeeze number. Damping due to the fluid layer is shown to be amplitude-dependent.