Compressible effects in microchannel flows

Abstract

The direct simulation Monte Carlo (DSMC) method, as an alternative numerical method, is used for simulating airflow in many micro-electro-mechanical-system (MEMS). In this application, due to the breakdown of continuum assumption, the traditional methods, such as CFD etc., failed even at standard conditions. However, DSMC is a successful tool when it is applied to micro-scale geometry related to MEMS devices. In this paper, Simulations of the gaseous flow passing though microchannels in the slip-flow regime are compared with an analytical solution using the Navier-Stokes equations with slip velocity boundary condition. Excellent agreements have been achieved in fully developed flow region. In further investigation, the effects of pressure ratio are carried out. The gradient of the pressure along the channel direction dominates the motion of the flow.