Kunze S, Groll R, Besser B, Thöming J
Chemical Process Engineering, Universität Bremen, Leobener Str. 6, 28359, Bremen, Germany.
Center of Applied Space Technology and Microgravity, Universität Bremen, Am Fallturm 2, 28359, Bremen, Germany.
Sci Rep. 2022 Feb 8;12(1):2057. doi: 10.1038/s41598-022-05871-y.
Molecular diameters are an important property of gases for numerous scientific and technical disciplines. Different measurement techniques for these diameters exist, each delivering a characteristic value. Their reliability in describing the flow of rarefied gases, however, has not yet been discussed, especially the case for the transitional range between continuum and ballistic flow. Here, we present a method to describe gas flows in straight channels with arbitrary cross sections for the whole Knudsen range by using a superposition model based on molecular diameters. This model allows us to determine a transition diameter from flow measurement data that paves the way for generalized calculations of gas behaviour under rarefied conditions linking continuum and free molecular regime.
分子直径是众多科学和技术学科中气体的一项重要属性。针对这些直径存在不同的测量技术，每种技术都给出一个特征值。然而，它们在描述稀薄气体流动方面的可靠性尚未得到讨论，尤其是在连续流和弹道流之间的过渡范围情况。在此，我们提出一种方法，通过使用基于分子直径的叠加模型来描述整个克努森范围内具有任意横截面的直通道中的气体流动。该模型使我们能够从流动测量数据中确定一个过渡直径，为稀薄条件下连接连续介质和自由分子区域的气体行为的广义计算铺平道路。
