DSMC Simulation of the Effect of Needle Valve Opening Ratio on the Rarefied Gas Flows inside a Micronozzle with a Large Length-to-Diameter Ratio

The cold gas micro-propulsion system can provide low noise and ultra-high accuracy thrust for satellite platforms space gravitational wave detection, high-precision earth gravity field measurement. In this study, the effect of different needle valve opening ratios on rarefied flow characteristics a micro-nozzle in was investigated based DSMC method. special feature currently studied is that it has section micro-channel with large length–diameter ratio up to 4.5. Due extremely small displacement nozzle (minimum 1.7 μm), finely structured mesh used. molecular particle macro inside were calculated conditions from 5% 98%. throttling throat significant micro-nozzle; especially under tiny opening, more significant. spatial distribution continuous flow, transition free varies at ratios. As increases, will gradually fill microfluidic region.