Study of Separation Zone of Rarefied Flows through Micro/Nano BackwardFacing Steps

In this study we use direct simulation Monte Carlo (DSMC) method to simulate subsonic nitrogen flow through micro/nano scale backward-facing step. This paper investigates the effect of the temperature and pressure on the flow fluid and separation zone of the step geometry. Increasing temperature of incoming flow makes remarkable variations in separation zone such as increased velocity magnitude and separation length. We observed that increasing Twall reduces the length of this region. Our results showed that separation zone length is less sensible to the variations of pressure ratio.

Keywords:

Direct simulation of Mont Carlo , rarefied gas flow , step flow , separation region