Hydro-Dynamic Characteristics of Gas-Liquid Two-Phase Flow in Ultra-Small Capillary Tubes

用20、25、50、80和100微米的孔径对空气-水和汽水两相流特性进行了直观观察。D.由硅石或石英制成的管子。本工作中使用的光学系统包括一个放大图像高达150倍的显微镜，一个高速摄像机和一台个人计算机。整个系统的空间分辨率为0.4微米。1）在直径小于100 μ m的微通道内，可以观察到多种两相流流型，包括泡状流、弹状流、液团流、液环流、环形膜流和雾状流。具体而言，液环流动是我们的新发现之一。2）已经证实，表面条件，如表面污染和润湿性是主导的影响，在两相流在微通道。一个非常有趣的观察结果是，在一个经过物理和化学处理的非常干净的系统中，几个气栓通过一个气杆连接起来，就像“烤肉串”一样。提出了一种适用于20 μ m圆管的两相流流型转换图。4）Armand关联式和修正的奇泽姆关联式分别验证了截面平均含气率和压降之间的良好关联。5）基于实验观察和数值模拟，我们提出了一个气泡动力学模型，该模型考虑了气泡之间施加的两个相互作用力。

Air-water and steam-water two-phase flow characteristics have been observed visually using 20, 25, 50, 80 and 100 microns i. d. tubes made of either silica or quartz. The optical system used in the present work consists of a microscope magnifying the images up to 150 times, a high-speed video camera and a personal computer. The spatial resolution of the whole system was 0.4 microns. Following conclusions have been drawn from the present work.1) More than several two-phase flow patterns were observed in micro-channels of diameter smaller than 100 microns, including bubbly, slug, Iiquid lump flows, Iiquid ring, annular film, and mist flows. Specifically, the liquid ring flow is one of our new findings.2) It has been confirmed that surface conditions such as surface contamination and the wettability are dominant effects in two-phase flows in micro channels. A very interesting observation is That, in a very clean system both physically and chemically treated, several gas slugs were connected by a gas stem just like "Yakitori". We named this newly found two-phase flow pattern as skewered slug flow.3) We proposed a two-phase flow pattern transition map for a 20-micron tube.4) It has been confirmed that the cross-sectional average void fraction and pressure drop are well Correlated by the Armand correlation and the modified Chisholm correlation, respectively.5) Based on our experimental observation and numerical simulation, we have proposed a bubble dynamic model taking into account two interaction forces exerting between the bubbles.