Study Of Transitional Regime Gas Flows Over A Backward-Facing Step

As in the macro-scale conventional counterparts, microscale flow systems require robust simulation tools for early-stage design iterations. This paper concentrates on a typical such flow process, namely flow over a backward facing step. Direct simulation Monte Carlo (DSMC) is used as the simulation tool. Separating the macroscopic velocity from the molecular velocity through the use of the IP method eliminates the high-level of statistical noise as typical in DSMC calculation of low-speed flows. The non-isothermal IP method is modified to incorporate the pressure boundary conditions, which are expected to be more prevalent in design of thermal management systems. The flow mechanisms over a backward-facing step in a microchanael at different pressures are investigated. The range of parameter values for this investigation are: Re from 0.03 to 0.64, Ma from 0.013 to 0.083, and Kn from 0.24 to 4.81, all based on maximum values