壁面与气体分子间作用力对微尺度气体润滑性能的影响  

Influence of molecular forces between gas molecules and the walls on micro scale gas lubrication

作　　者：张延瑞[1] 孟永钢[1] 

机构地区：[1]清华大学精密仪器与机械学系,摩擦学国家重点实验室,北京100084

出　　处：《清华大学学报（自然科学版）》2010年第9期1476-1479,共4页Journal of Tsinghua University(Science and Technology)

基　　金：国家杰出青年科学基金资助项目(50525515);国家“九七三”重点基础研究项目(2003CB716205)

摘　　要：当微尺度气体润滑轴承的间隙达到数nm时,固体表面与气体分子间的Van der Waals力对气体轴承的性能会产生不可忽视的影响。该文假设轴承壁面对气体分子存在Van der Waals作用力,并利用DSMC(direct simulation Monte Carlo)方法结合分子在表面力作用下的运动算法,研究了该作用力的强度和作用范围对微尺度气体润滑的影响。结果表明:气体轴承中分子密度的分布与不考虑表面力时相比发生了改变,与表面力的作用强度和作用距离有关;壁面的吸引力加剧了分子在壁面附近的聚集,排斥力则相反。When bearing clearances get down to several nanometers in micro scale gas lubrication,the Van der Waals force between the solid surfaces and the gas molecules significantly affects the performance of gas slider bearings.The Van der Waals force between solid surfaces and gas molecules was analyzed to investigate the effect of the molecular force intensity on the behavior of micro-scale gas slider bearings,using both the direct simulation Monte Carlo（DSMC） method and the molecule movement algorithm.The results show that the gas density changes significantly compared with the case having no inter molecular forces.The attraction force from the solid wall enhances aggregation of molecules near the wall while a repulsive force has the opposite effect.

关 键 词：Vander Waals力 DSMC(direct simulation MONTE Carlo)方法 微尺度气体轴承 

分 类 号：TH117.2[机械工程—机械设计及理论]