矩形微通道Knudsen泵中的气体传输特性研究  

Study of Transmission Characteristics of Gas in A Rectangular Knudsen Pump

作　　者：王晓伟 张志军[1] 张文青 苏天一 张世伟[1] WANG Xiaowei;ZHANG Zhijun;ZHANG Wenqing;SU Tianyi;ZHANG Shiwei(School of Mechanical Engineering and Automation,Northeastern University,Shenyang 110819,China)

机构地区：[1]东北大学机械工程与自动化学院

出　　处：《真空与低温》2020年第1期73-81,共9页Vacuum and Cryogenics

基　　金：国家自然科学基金项目(31371873、31000665、51176027、31300408);CAST-BISEE(北京卫星环境工程研究所)创新基金项目

摘　　要：Knudsen泵是一种基于微尺度条件下的热蠕流效应诱导气体从低温侧向高温侧流动的微型泵。为探究气体种类和分子模型对气体在Knudsen泵通道中传输特性的影响,运用直接模拟蒙特卡罗(DSMC)方法,针对经典的矩形微通道开展了研究。文中分别考虑了三种气体(Ar、N2和O2)和三种分子模型(HS、VHS和VSS)在不同工况压力下的变化情况。研究发现,不同种类气体和分子模型不会引起通道中宏观流场的明显变化。对于分子质量较轻的气体,其具有更强的热蠕流效应,且其最强热蠕流效应所对应的压力越大。对于分子模型,VHS模型的热蠕流效应最强,HS模型的热蠕流效应最弱。因此,相比于更能反映真实气体分子运动规律的VSS模型而言,当采用VHS模型时会高估泵的性能,反之,采用HS模型时会低估泵的性能。Knudsen pump is a kind of micro-pump where gases flow from the low temperature side to the high temperature side induced by thermal creep effect,based on the micro-scale condition.In order to investigate the influence of the gas species and molecular model on the transmission characteristics of gas in the micro-channels of Knudsen pump,the method of Direct Simulation Monte Carlo(DSMC)is applied to investigate the classic rectangular micro-channel.The variations of three kinds of gases(Ar,N2 and O2)and three kinds of molecular models(HS,VHS and VSS)are considered respectively under the condition of different working pressures.From the research,it is found that different kinds of gas species and molecular models will not lead to the obvious change of the macroscopic flow field in the micro-channel.For the gases with a light molecular mass have a stronger thermal creep effect,and the maximum thermal creep effect corresponds to a large pressure.Regarding to molecular model,the thermal creep effect is the strongest for VHS model while the thermal creep effect is the weakest for HS model.Therefore,compared with VSS model which could reflect moving rules of the real gas molecules better,application of VHS model will overestimate the performance of pump but underestimated by using HS model.

关 键 词：气体种类 分子模型 热蠕流 Knudsen泵 矩形微通道 DSMC 

分 类 号：TB75[一般工业技术—真空技术]