微尺度气体润滑的非平衡流效应分析  

Effect of Non-Equilibrium Flow on Micro Scale Gas Lubrication:A Simulation and Analytical Study

作　　者：杨琴[1] 张海军[2] 沈剑英[2] 顾晓军 

机构地区：[1]嘉兴学院数理与信息工程学院,嘉兴314001 [2]嘉兴学院机电工程学院,嘉兴314001 [3]Scientific Computing Department,STFC Daresbury Laboratory

出　　处：《真空科学与技术学报》2017年第10期1026-1031,共6页Chinese Journal of Vacuum Science and Technology

基　　金：国家自然科学基金项目(No.11102071);国家留学基金项目(No.201208330295);浙江省公益技术研究项目(No.2016C31051)

摘　　要：微尺度气体润滑中,引起微尺度气体润滑压力降低的原因在于润滑流的非平衡流效应。微尺度气体润滑的非平衡流效应不仅会引起壁面气流速度滑移,而且会引起润滑气流热通量的变化。本文首先给出了基于Boltzmann矩方程的微尺度气体润滑模型(矩方程润滑模型);其次,与FK润滑模型和直接模拟Monte Carlo方法的分析结果比较,验证基于矩方程润滑模型的有效性;再次,基于矩方程润滑模型,分析不同轴承数情形下微尺度气体润滑的非平衡流效应。研究表明,随着轴承数的增大,微尺度气体润滑的非平衡流效应增强,表现为壁面速度滑移及热通量均增大。与壁面速度滑移的变化相反,随着轴承数的增大,非平衡流效应引起气膜压力及承载力的变化较小。这一反常现象的原因在于气体的可压缩性。The micro scale gas lubrication was mathematically formulated withthe moment equationslubrication model,derived on Boltzmann moment equations,and numerically simulated in Monte Carlo method.The effect of the non-equilibrium flow at different bearing numbers on the decrease of the lubrication pressure, possibly originated from the velocity-slip on the wall and changes in heat flux,was investigated.The pressure profile evaluated with the novel moment equationslubrication modelwas roughly in agreement with those calculated with FK model and simula-ted in direct Monte Carlomethod.The simulated results show that thenon-equilibrium flow has a major impact.For instance,as the bearing number increased,the non-equilibrium flow effect becomes stronger because of the rapid in-creases of velocity slip and heat flux;in contrast,the gas film pressure and load capacitychangedrather weakly,possi-bly because of the compressibility of gases.

关 键 词：微尺度气体润滑 非平衡流 速度滑移 热通量 

分 类 号：TH117.2[机械工程—机械设计及理论]