Squeezing flow between rigid tilted surfaces: A general solution and case study for MEMS

Squeeze film flow occurs when two surfaces move in a normal direction relative to each other and is a phenomenon of importance to many engineering systems, from macro to microscale. Squeeze film damping is widely used in large-scale rotating machinery but even more so presently in microsystems. In the latter case, for modelling purposes, the two surfaces producing the squeeze film flow are typically assumed perfectly parallel, which is often not the case in practice. This paper presents a general formula for squeezing flow between two rigid surfaces for both parallel and tilted configurations in the 1-dimensional case (2-dimensional flow). The solution is derived from the Reynolds equation. The results in the parallel case compare favorably to previous literature data. A case study is presented for plates with dimensions characteristic of microelectromechanical systems. The important contribution of this paper is to isolate and study this “tilt effect” which can contribute to discrepancies and confusion in interpreting squeeze film behaviour, particularly at the microscale.