Measurement of the liquid film thickness in micro tube slug flow
Measurement of the liquid film thickness in micro tube slug flow
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DOI：
10.1016/j.ijheatfluidflow.2009.02.019
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发表时间：
2009-10-01
影响因子：
2.6
通讯作者：
Shikazono, Naoki
中科院分区：
文献类型：
--
作者：
Han, Youngbae;Shikazono, Naoki
弹状流是微细管内两相流的典型流型之一。众所周知，在微尺度管壁与汽泡之间形成的薄液膜对微尺度管的传热起着重要的作用。在本研究中，进行了实验，以澄清的影响的微小管两相流中的薄液膜的形成的参数的影响。采用激光聚焦位移计测量薄液膜的厚度。空气、乙醇、水和FC-40被用作工作流体。使用具有五种不同直径（D = 0.3、0.5、0.7、1.0和1.3mm）的圆管。结果表明，液膜厚度仅由毛细管数决定，在毛细管数较小时，惯性力的影响可以忽略不计。然而，随着毛细管数的增加，惯性力的影响不可忽略。在较高的毛细管数下，液膜厚度随雷诺数的变化呈现最小值。研究了气泡长度、液塞长度和重力对液膜厚度的影响。提出了基于毛细管数、雷诺数和韦伯数的初始液膜厚度的实验关联式。(C)2009 Elsevier Inc. All rights reserved.
Slug flow is one of the representative flow regimes of two-phase flow in micro tubes. It is well known that the thin liquid film formed between the tube wall and the vapor bubble plays an important role in micro tube heat transfer. In the present study, experiments are carried out to clarify the effects of parameters that affect the formation of the thin liquid film in micro tube two-phase flow. Laser focus displacement meter is used to measure the thickness of the thin liquid film. Air, ethanol, water and FC-40 are used as working fluids. Circular tubes with five different diameters, D = 0.3, 0.5, 0.7, 1.0 and 1.3 mm, are used. It is confirmed that the liquid film thickness is determined only by capillary number and the effect of inertia force is negligible at small capillary numbers. However, the effect of inertia force cannot be neglected as capillary number increases. At relatively high capillary numbers, liquid film thickness takes a minimum value against Reynolds number. The effects of bubble length, liquid slug length and gravity on the liquid film thickness are also investigated. Experimental correlation for the initial liquid film thickness based on capillary number, Reynolds number and Weber number is proposed. (C) 2009 Elsevier Inc. All rights reserved.