Multiple-Relaxation-Time Lattice Boltzmann Model for Squeeze Film Air Damping of Large Knudsen Number in MEMS

摘要

The study of squeeze-film damping (SFD) of micro-resonant devices under large Knudsen (Kn) number is of great significance for the design of micro-nano devices. In the case of large Kn number, the Reynolds equation based on the continuum assumption is no longer applicable, so new methods are needed to research SFD. In this paper, a Multiple-Relaxation-Time Lattice Boltzmann Model (MRT-LBM) is established for the SFD of rectangular cantilever in transition regime, and the quality factor results are compared with experimental results together with the results of Monte Carlo (MC) model and FEM simulation. Moreover, the effects of Kn number and the size of the structure are studied. The results show that the MRT-LBM model is consistent with the experimental results under various conditions, and the MC model and FEM simulation show large deviations.