Mass flow rate prediction of temperature-driven gas flows through divergence micro/nanochannels

This paper presents an investigation of the mass flow rate of rarefied gaseous flow in divergent micro/nano channels compared with the results of straight channels. Direct simulation Monte-Carlo (DSMC) method is used to solve rarefied flow over a broad range of Knudsen number accurately. We observed that the mass flow rate increases with the divergence angle. The effect of channel aspect ratio (AR) is not crucial on the mass flow rate in lower Knudsen numbers. However, the mass flow rate increases with the divergence angle when Knudsen number is high. We show that enhanced thermal creep effect is the main source of the mass flow rate increase if the wall temperature gradient is increased.