Simulation And Analysis Of Rarefied Flow In Micro Nozzle Using DSMC

With the rapid development of micro-satellite technology in China, micro nozzle being the key component of the micro-propulsion system has been paid much effort of research, in this realm, the simulation of rarefied flow in the micro nozzle is the key step for the design and performance improving of micro nozzle. The research of flow characteristics in the micro-scale nozzle will make great significance for guiding the design of spatial micro thruster and the micro-electro-mechanical power system. In this paper, we focus on some typical nozzles of micron dimension being developed for micro-propulsion system in and abroad, and make modeling and simulation analysis of the performance of rarefied flow in the micro nozzle.The flow characteristic of rarefied gas is very complicated in its dynamics problem. Due to the small gas density and the micro scale of working components, the mean free path of the gas molecule is in the same order with the feature size of micro nozzle, this makes the gas flow described by non-linear and coupling differential and integral equations, whose analytic result being very hard to get.Based on the comprehensive analyses of the various solutions in rarefied gas dynamics and the fact in this research, the modeling and calculation for the flow in micro nozzle are carried out by using the direct simulation Monte-Carlo method, and the analysis of internal flow variations under some different working conditions are performed. First, the influences of inlet pressure variations on micro nozzle's performance are obtained by analyzing the variations of various flow parameters in micro nozzle accordingly. In addition, the variations of the viscous effect with different inlet temperature is studied, the changing law of thrust and thrust efficiency with temperature is analyzed. Finally, the influences of different throat size on the performance of micro nozzle are analyzed comparatively, which can be referred to the design of micro nozzle geometry.The simulation code for the calculation of inlet flow is developed based on various models using DSMC method, through the simulation of micro-scale flow of various working conditions, we get the flow properties of the micro-scale...