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

超细毛细管内气液两相流的水动力特性

• 批准号: 13650179
• 负责人: SERIZAWA Akimi
• 金额: $ 2.11万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650179/
• 关键词: micro-capillary tube; gas-liquid two-phase flow; flow pattern; visual observation; void fraction; pressure drop; 超マイクロキヤピラリー流路

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.

用石英或石英制成的直径分别为20、25、50、80和100微米的管子，对空气-水和蒸汽-水两相流动特性进行了直观观察。本研究中使用的光学系统包括一台放大150倍的显微镜、一台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微米的微流道中观察到了多种两相流流型，包括泡状流、弹状流、液块流、液环流、环膜流和雾状流。具体地说，液环流动是我们的新发现之一。2)已经证实，表面污染和润湿性等表面条件是微通道内两相流动的主要影响因素。一个非常有趣的观察是，在一个经过物理和化学处理的非常干净的系统中，几个气体段塞由一个气柱连接起来，就像“Yakitori”一样。3)提出了20微米管内两相流流型转变图。4)用Armand关联式和修正的Chisholm关联式分别对截面平均含气率和压降进行了很好的关联。5)在实验观察和数值模拟的基础上，提出了考虑气泡间相互作用力的气泡动力学模型。

项目成果

Feng, Z.P., Serizawa, A: "A Review of Gas-Liquid Two-Phase Flow Hydraulics in Micro-Channels"日本機械学会「マイクロチャンネル内の流動と熱伝達」研究分科会成果報告書(P-SC295). 3-19 (2001)

Feng, Z.P., Serizawa, A：“微通道中气液两相流水力学的综述”日本机械工程师学会“微通道中的流动和传热”研究小组委员会结果报告（P-SC295）。 3-19 (2001)

Serizawa, A., Feng.Z.P.: "Heat Exchanger Design Update(共著)"Begell House(印刷中). (2003)

Serizawa, A., Feng.Z.P.：“热交换器设计更新（合著者）”Begell House（印刷中）。

Serizawa, A.: "Two-Phase Flow in Micro-Channels"Proc. of the Workshop on Two-Phase Flow and Phase Change Heat Transfer. (Invited Lecture), July 30-31, 2001, Pohang, Korea. 9-28 (2001)

Serizawa, A.：“微通道中的两相流”Proc。

Serizawa, A: "Two-Phase Flow in Micro-Channels"Proc. of the Workshop on Two-Phase Flow and Phase Change Heat Transfer, July 30-31,2001,Pohang, Korea (2001) 9-28 (Invited Lecture). (2001)

Serizawa，A：“微通道中的两相流”Proc。

Serizawa, A. and Feng, Z. P.: "Two-Phase Flow in Micro-Channels"Proc. of the 4^<th> International Conference on Multiphase Flow. (Invited Keynote Lecture), May 27-Junel, 2001, New Orleans, Lousiana, USA. (2001)

Serizawa, A. 和 Feng, Z. P.：“微通道中的两相流”Proc。