Characteristics of liquid–liquid slug flow are investigated in a microchannel with focus on the leakage flow that bypasses droplets through channel gutters. The results show that the leakage flow rate varies in a range of 10.7–53.5% and 8.3–30.9% of the feed flow rate, during the droplet formation (i.e., at T-junction) and downstream flow (i.e., in the main channel), respectively, which highly depends on Ca number and wetting condition. Empirical correlations are proposed to predict them for perfectly and partially wetting conditions. Leakage flow contribution is further used to improve the Garstecki model for size scaling in order to extend its suitability for both squeezing and shearing regimes. The instantaneous flow rates of the immiscible phases are found to fluctuate periodically with the formation cycles, but in opposite behavior. The effect of the presence of leakage flow on such fluctuation are investigated and compared with gas–liquid systems. © 2017 American Institute of Chemical Engineers AIChE J, 2017

中文翻译：

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微流控T型接头中液-液团塞流的形成：流体特性和泄漏流的影响

在一个微通道中研究了液-液团状塞流的特性，重点研究了绕过通道槽的液滴绕过的泄漏流。结果表明，在液滴形成期间（即在T形结处）和下游流动（即在主通道中），泄漏流速在进料流速的10.7％至53.5％和8.3-30.9％的范围内变化），这在很大程度上取决于Ca数和润湿条件。提出了经验相关性，以预测它们在完全和部分润湿条件下的状态。漏流贡献进一步用于改进Garstecki模型的尺寸缩放比例，以扩展其在挤压和剪切状态下的适用性。发现不混溶相的瞬时流速随形成周期而周期性地波动，但是行为相反。研究了泄漏流对这种波动的影响，并与气液系统进行了比较。©2017美国化学工程师学会AIChE的Ĵ，2017年