• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2017, Vol. 53 ›› Issue (24): 70-76.doi: 10.3901/JME.2017.24.070

• 多相流测试新技术与新方法 • 上一篇    下一篇

剪切应力影响下近壁微液膜测量技术及波动特性研究

王科1,2,3, 叶晶4, 龚圣捷5, 马卫民3   

  1. 1. 中国石油大学(北京)机械与储运工程学院 北京 102249;
    2. 过程流体过滤与分离技术北京市重点实验室 北京 102249;
    3. 瑞典皇家工学院核电安全系 斯德哥尔摩 10693 瑞典;
    4. 中船重工集团公司第七一一研究所 上海 201108;
    5. 上海交通大学核科学与工程学院 上海 200240
  • 收稿日期:2017-01-07 修回日期:2017-09-04 发布日期:2017-12-20
  • 通讯作者: 王科(通信作者),男,1982年出生,博士,讲师。主要研究方向为气液两相流和沸腾传热。E-mail:wang_ke@cup.edu.cn
  • 作者简介:叶晶,男,1984年出生,博士,工程师。主要研究方向为气液两相流和传热。E-mail:yejing2011@gmail.com;龚圣捷,男,1979年出生,博士,副教授。主要研究方向为沸腾传热试验研究,核安全事故分析等。E-mail:gsj@sjtu.edu.cn;马卫民,男,1968年出生,博士,副教授,博士研究生导师。主要研究方向为气液两相流和沸腾传热,反应堆严重事故分析等。E-mail:weimin@kth.se
  • 基金资助:
    欧洲NORTHNET、国家自然科学基金(51706245)和中国石油大学(北京)科研基金(2462016YJRC029)资助项目。

Experimental Study on the Dynamics of a Thin Liquid Film under Shearing Force

WANG Ke1,2,3, YE Jing4, GONG Shengjie5, MA Weimin3   

  1. 1. College of Mechanical and Transportation Engineering, China University of Petroleum, Beijing 102249;
    2. Beijing Key Laboratory of Process Fluid Filtration and Separation, Beijing 102249;
    3. Division of Nuclear Power Safety, Royal Institute of Technology(KTH), Stockholm 10693, Sweden;
    4. Shanghai Marine Diesel Engine Research Institute, Shanghai 201108;
    5. School of Nuclear Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240
  • Received:2017-01-07 Revised:2017-09-04 Published:2017-12-20

摘要: 基于尺度分离理论,近壁微液膜波动特性对临界热负荷的产生有至关重要的影响。针对水平管内分层流动近壁微液膜在气流剪切应力作用下的波动特性进行研究,分析声学法,射线法,电学法和光学法等不同检测方法在近壁薄液膜厚度测量上的应用,并比较各种方法的优缺点。最终采用光学法,即利用光谱共焦位移传感器,对不同气、液流速条件下近壁微液膜进行测量,分析剪切夹带对液膜厚度变化的影响规律,获得液膜撕裂的临界条件。研究结果表明:微液膜平均厚度在气流剪切夹带影响下随气速的增大而减小。由于液滴夹带现象影响程度的不同,在不同气、液流速条件下,试验段出口处液膜平均厚度液膜呈现线性或非线性的变化趋势。气流剪切应力增大时,液膜厚度超过临界厚度即发生撕裂现象,液膜撕裂存在随机性,当壁面条件一定时,临界液膜厚度不随气、液流速的变化而变化,但在高气、液流速条件下液膜波动加剧。

关键词: 界面失稳, 近壁微液膜, 气液两相流, 液滴夹带

Abstract: The "scales-separation" phenomenon indicates that high heat-flux boiling and boiling crisis is dominated by micro-hydrodynamics of liquid microlayer on the heater surface. The techniques for liquid film measurement such as acoustic methods, nucleonic techniques, electrical methods, and optical methods are discussed in detail. Accordingly, a confocal optical sensor system is used to detect the dynamics of liquid film sheared by the co-flowing air from above in a horizontal aluminum channel. The impact of the gas shearing on film behaviors is analyzed and the integrity of liquid film is discussed in detail. The results indicate that the liquid film thickness decreases due to the entrainment and shows a linear or nonlinear variation under different flow conditions. Additionally, for a specific surface, the critical film thickness for an integral film is found to have no relation with the gas and liquid flow rates but the fluctuation of the liquid film increases with the increasing gas velocity.

Key words: entrainment, instability, micro-layer, two-phase flow

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