Measurements and computations of mass flow and momentum flux through short tubes in rarefied gases
Measurements and computations of mass flow and momentum flux through short tubes in rarefied gases
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DOI：
10.1063/1.2345681
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发表时间：
2006-09-01
影响因子：
4.6
通讯作者：
Markelov, G. N.
中科院分区：
文献类型：
--
作者：
Lilly, T. C.;Gimelshein, S. F.;Markelov, G. N.
从 20 世纪 60 年代到 20 世纪 80 年代，出于基本和实际原因，通过孔口和短管的气流得到了广泛的研究。这些流量是各种现代气体驱动仪器的基本且通常重要的元素。微米和纳米级技术的最新进展为从临床分析到生化检测再到航空航天推进等各个应用领域的新一代小型化设备铺平了道路。后者是本研究的主要兴趣领域，通过动力学和连续介质方法对稀薄气体通过厚径比从 0.015 到 1.2 变化的短管流入真空进行了实验和数值研究。使用的氦气和氮气的雷诺数范围为 0.02 至 770（基于管直径），对应的努森数为 40 至约 0.001。检查相对较薄和较厚的管的推进特性。对于质量流量和动量通量，观察到实验结果与数值结果之间具有良好的一致性，后者针对实验设施背景压力进行了校正。对于质量流量和动量通量与压力的厚薄管比，在努森数约为 0.5 时观察到最小值。短管推进效率比细孔推进效率高得多。发现表面镜面度对较厚管比冲的影响相对较小。 (c) 2006 年美国物理研究所。
Gas flows through orifices and short tubes have been extensively studied from the 1960s through the 1980s for both fundamental and practical reasons. These flows are a basic and often important element of various modern gas driven instruments. Recent advances in micro- and nanoscale technologies have paved the way for a generation of miniaturized devices in various application areas, from clinical analyses to biochemical detection to aerospace propulsion. The latter is the main area of interest of this study, where rarefied gas flow into a vacuum through short tubes with thickness-to-diameter ratios varying from 0.015 to 1.2 is investigated both experimentally and numerically with kinetic and continuum approaches. Helium and nitrogen gases are used in the range of Reynolds numbers from 0.02 to 770 (based on the tube diameter), corresponding to Knudsen numbers from 40 down to about 0.001. Propulsion properties of relatively thin and thick tubes are examined. Good agreement between experimental and numerical results is observed for mass flow rate and momentum flux, the latter being corrected for the experimental facility background pressure. For thick-to-thin tube ratios of mass flow and momentum flux versus pressure, a minimum is observed at a Knudsen number of about 0.5. A short tube propulsion efficiency is shown to be much higher than that of a thin orifice. The effect of surface specularity on a thicker tube specific impulse was found to be relatively small. (c) 2006 American Institute of Physics.