NUMERICAL INVESTIGATION OF GASEOUS MICROCHANNEL FLOW IN TRANSITION REGIMES.

Pressure-driven low subsonic gaseous flows in a microchannel are studied numerically by the Direct Simulation Monte Carlo (DSMC) method. The variable Hard Sphere (VHS) molecular model and Larsen-Borgnakke procedures are adopted. The Knudsen number (Kn) is adjusted by varying inlet/outlet pressure for a range of transition regimes. Cases of different channel aspect ratios and wall temperatures with the fixed inlet/outlet pressure or constant average pressure-gradient boundary conditions are investigated. The results indicate that both the channel length and heat transfer affect the rarefaction of the flow. The downstream variations in flow properties are strongly dependent on Kn, aspect ratio, and heal transfer, and generally are in qualitative agreement with the Fanno/Rayleigh theory. [ABSTRACT FROM AUTHOR]