Comprehensive assessment of viscous heat generation in rarefied gas microflows

An accurate simulation will assist to understand the behavior of rarefied gas flows in MEMS devices. This is useful for obtaining an optimal design for these devices. In this paper, we will comprehensively investigate the effect of viscous heat generation on the rarefied gas microflows in the microcavity and Couette flows. The considered cases have the Knudsen number ranging from 0.05 to 1, and working gas as argon. Both of the temperature jump conditions were recently derived including the viscous heat generation term such as the new type of Smoluchowski and the modified Patterson temperature jump conditions are adopted in the present work. The simulation results show that the viscous heat generation significantly affects the gas temperatures, and it makes a reduction of the gap between the CFD and DSMC data. The simulation results of the modified Patterson jump condition are close to the DSMC data for the high Kn cases, Kn = 0.5 and 1 while those of the new type of Smoluchowski jump condition are not. Keywords: viscous heat generation, temperature jump condition, rarefied gas microflows, temperatures.