Knudsen flow 75 years on: the current state of the art for flow of rarefied gases in tubes and systems
Knudsen flow 75 years on: the current state of the art for flow of rarefied gases in tubes and systems
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DOI：
10.1088/0034-4885/49/10/001
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发表时间：
1986-10
影响因子：
18.1
通讯作者：
W. Steckelmacher
中科院分区：
文献类型：
--
作者：
W. Steckelmacher
在简要的历史介绍之后，概述了稀薄气流的最新研究与克努森的早期工作。 1908 年 10 月提交的第一篇论文（发表于 1909 年）引发了 Knudsen、Smoluchowski (1910) 以及稍后 Gaede (1913) 和 Langmuir (1912) 的激烈活动。这也涵盖了向已经完善的流体动力流动的过渡，该流体动力流动以平均自由程与临界设备尺寸的比率表示：现在称为克努森数。分子从表面的解吸、蒸发和散射是用努森余弦散射定律描述的。同样于 1909 年推出的用于测定蒸气压的努森流出法已成为研究离解、化学键合和汽化过程本身相关问题的主要工具。 Clausing (1926) 提出了传输概率的概念，作为电导的替代方案，仍称为 Clausing 因子，并提供了在长管和短管中更准确评估传输概率的程序。对这些早期努力的许多误解已经出现在有关真空科学和技术的文献和最新书籍中。然而，详细的研究已经阐明了气体-表面相互作用的问题；管内的气体流动已通过克劳辛型积分方程和基于适用于更复杂系统的蒙特卡罗分析程序的统计计算技术来解决。结果已通过分子冲击压力探针测量技术得到实验证实。
Following a brief historical introduction an overview is given relating the most recent studies of rarefied gas flow to the early work of Knudsen. The first paper submitted in October 1908 (published in 1909) initiated a period of intense activity by Knudsen, Smoluchowski (1910) and, a little later, by Gaede (1913) and Langmuir (1912). This also covered the transition to the already well established hydrodynamic flow expressed in terms of the ratio of mean free path to critical apparatus dimension: which is now referred to as the Knudsen number. The desorption, evaporation and scattering of molecules from surfaces was described in terms of the Knudsen cosine law of scattering. The Knudsen effusion method for determining vapour pressure, also introduced in 1909, has become the main tool for studies of the related problem of the dissociation, chemical bonding and the vaporisation process itself. Clausing (1926) developed, as an alternative to conductances, the concept of transmission probability, still referred to as the Clausing factor, and provided a procedure for their more accurate evaluation in long and short tubes. A number of misconceptions of these early efforts have found their way into the literature and current books on vacuum science and technology. However, detailed studies have clarified the problem of gas-surface interactions; the gas flow in tubes has been tackled with Clausing-type integral equations and by statistical computation techniques based on Monte Carlo analysis procedures adaptable to more complex systems. Results have been confirmed experimentally using molecular-impact pressure probe measuring techniques.