稀薄气体流动的粒子图像测速实验研究  

Experimental Study on Particle Image Velocimetry of Rarefied Gas Flow

作　　者：朱志鹏[1] 秦彬玮 张英莉 岳向吉[1] 巴德纯[1] ZHU Zhi-peng;QIN Bin-wei;ZHANG Ying-li;YUE Xiang-ji;BA De-chun(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,辽宁沈阳110819

出　　处：《真空》2021年第1期38-44,共7页Vacuum

基　　金：国家重大科学仪器设备开发专项子课题“涡旋干泵流场及热场分析”(2013YQ24042101)。

摘　　要：建立了一套可对真空度进行调节的实验装置,从大气压开始逐渐降低系统压力,进行系列稀薄气体流动的PIV流场实验。系统压力从101kPa、90kPa逐次降至10kPa,使用所选粒子在不同系统压力下分别进行PIV实验获得测量区域流场分布情况。运用计算流体力学的方法模拟大气压条件下实验区域的内部流动,对比结果发现该种条件下数值模拟结果很好的与PIV实验测得流场结构吻合,从而验证了实验和数值模拟的可靠性和稳定性。通过对PIV实验结果进行分析:克努森数Kn≤0.14实验测量可以获得较好的流场效果;当0.14<Kn≤0.29测量区域流态仍然完整但测得的流场流速偏小;0.29<Kn≤0.86实验测得的速度显著降低且流态不完整。In this paper,a series of particle image velocimetry(PIV)flow field experiments of rarefied gas flow were carried out by setting up a set of experimental apparatus that can adjust the vacuum degree and gradually reduce the system pressure from atmospheric pressure.The system pressure was successively reduced from 101 kPa and 90 kPa to 10 kPa,and PIV experiments were carried out with selected particles under different system pressures to obtain the flow field distribution in the as-measured area.The CFD method was used to simulate the internal flow in the experimental area under atmospheric pressure,and the comparison results show that the numerical simulation results are in good agreement with the flow field structure measured by PIV experiment,thus verifying the reliability and stability of the experiment and numerical simulation.By analyzing the results of PIV experiment:Knudsen number Kn≤0.14 better flow field effect can be obtained by experimental measurement;When 0.14<Kn≤0.29,the flow state in the measured area is still complete but the measured flow field velocity is relatively small;When 0.29<Kn≤0.86,the measured velocity is significantly reduced and the flow pattern is incomplete.

关 键 词：稀薄气体 粒子图像测速 数值模拟 示踪粒子 跟随性 

分 类 号：TB71[一般工业技术—真空技术]