考虑稠密气体效应的微尺度气体轴承模拟  

Simulation of micro scale gas bearings with dense gas effect

作　　者：张延瑞[1] 孟永钢[1] 

机构地区：[1]清华大学,北京100084

出　　处：《应用力学学报》2010年第4期656-663,共8页Chinese Journal of Applied Mechanics

基　　金：国家杰出青年科学基金(50525515);创新研究群体基金(50721004)

摘　　要：当气体流动区的局部压力升高到一定程度时,气体稠密效应对其输运特性的影响不可忽略,其影响可以用Enskog理论来描述。利用直接模拟蒙特卡罗(DSMC)方法以及考虑气体分子稠密效应的衍生方法对气体粘度随特征尺度的变化规律和气体粘度随密度变化的规律进行了计算分析,在此基础上研究了考虑稠密效应的微尺度气体轴承的承载能力。计算结果表明,稠密效应在抵消掉气体稀薄效应的同时还改变了输运系数和气体薄膜的润滑特性,提高了气体轴承的承载能力。When local gas pressure reaches to certain level in gas lubrication,the dense gas effect is no longer negligible,and the transportation behaviors of gas molecules are changed by dense gas effect,which can be described by Enskog theory.In this article,the CBA and ESMC methods,which are developed from DSMC and capable of dealing with the dense gas effect,are used to investigate the variations of gas shearing viscosity with the characteristic size and the gas density.Based on the simulation results,the load capacity of micro-scale gas slider bearings is studied by taking the dense gas effect into account.The simulation results show that dense gas effect counteracts the rarefied gas effect,at the same time changes the transportation coefficients and characteristic of molecular gas-film lubrication,leads to an increase in the load capacity of gas slider bearings.

关 键 词：稠密气体 直接模拟蒙特卡罗 输运系数 气体润滑 

分 类 号：TH20[机械工程—机械制造及自动化] TK16[动力工程及工程热物理—热能工程]