涡轮分子泵入口接管束流效应的蒙特卡洛计算  

Monte Carlo Simulation of Beaming Effect of Molecular Flow via Inlet Tube of Turbo Molecular Pump

作　　者：牟如意 张世伟[1] 张志军[1] 韩进[1] 

机构地区：[1]东北大学机械工程与自动化学院,沈阳110004

出　　处：《真空科学与技术学报》2017年第8期753-759,共7页Chinese Journal of Vacuum Science and Technology

基　　金：NSFC-广东联合基金(第二期)超级计算科学应用研究专项资助;国家超级计算广州中心

摘　　要：在入口管路束流效应和涡轮端盖反射作用的双重因素影响下,以纯分子流态经泵前入口管道流向涡轮分子泵环形一级动叶列抽气面处的气体分子,其入射密度是不均匀分布的。本文基于自由分子流态基本假设,建立入口直圆管道计算模型,采用试验粒子蒙特卡洛方法,利用Molflow+软件,模拟被抽气体分子经泵入口到涡轮叶列抽气面的飞行过程及行为;数值计算得到气体分子到达涡轮转子一级动叶列入射平面的密度分布和气体通过入口管道的传输几率,并分别经回归分析拟合给出二者的计算公式,可为涡轮分子泵抽气性能的后续研究提供更精确的理论数据;算例证明,以此分布计算分子泵一级动叶列的正向传输几率,比采用均匀分布假设的积分中值法的计算结果偏小。We addressed thenon-uniform distribution ofmolecular gas density,originated from beaming effect and reflection of turbo cover,in the inlet tube of turbo molecular pump. The gas flow field was mathematically modeled and numerically simulated with Monte Carlo simulator package Molflow ＋. The impact of the tube length and turbo-cover diameter on the transmission probability and radial density profile of the incident gas in the rotor-blade plane was investigated. The fitting formulae of the transmission probability and incident gas density were derived by regression analysis in terms of the simulated results. The forward transmission probability,computed by means of the simulated incident gas density profile,lies somewhere between those calculated in geometric mean and integral mean methods based on the assumption of uniform gas density distribution.

关 键 词：涡轮分子泵 分子密度分布 蒙特卡洛法 入口直接管 自由分子流 

分 类 号：TB752.27[一般工业技术—真空技术]