TABLE OF CONTENTS The DSMC method has been one of the most widely used tools for analyzing hypersonic rarefied gas flows (Moss et al. 1994). The method has been applied to a range of problems, for example, contaminant pollution over space platforms (Rault and Woronowicz 1995). Recent advances have resulted in procedures more efficient for dealing with complex three-dimensional geometry as well as significant reductions in the computational effort. Such advances have made practical the applications of DSMC to the calculations of the rarefied gas flow over the full Space Shuttle geometry (Bird 1990).
For microfluid flows in MEMS, the operating pressure can be near or even higher than the atmospheric pressure. Using DSMC to calculate such flows of high density can be quite demanding in both the computer memory and the computational time. Methods to deal with large variations of density have been proposed and applied successfully to many problems. These schemes generally require a significant amount of computer time for near-continuum conditions due to, partly, the increase of the collision frequency at high gas density. As such, further reductions in computational time are still needed to make the calculations of high-density, large-scale microfluid flow problems more affordable.
Parallel implementations of DSMC for high-speed rarefied gas applications have been reported in the literature (Wilmoth and Carlson 1992; Dietrich and Boyd 1995; LeBeau 1999). The computer platforms used include, for example, IBM SP-2 and CRAY-T3E. In recent years, hardware for personal computer (PC) has dramatically improved. This, when coupled with efficient...
