Abstract

The laws of drop formation are experimentally studied in narrow horizontal microchannels with rectangular section with heights from 50 to 150 μm. It is shown that there exists a new flow regime when the drops in the form of vertical liquid bridges move along the microchannel. Three mechanisms of formation of such drops are distinguished: formation directly near the liquid nozzle, departure of drops from liquid moving at the lateral sides of channel, and drop formation due to destruction of severely deformed drops and horizontal liquid bridges. It is established that the deformation of drops increases with increasing Weber number. It is demonstrated that the drops begin to deform when the first critical value of the Weber number is achieved and begin to be destroyed when the second one is achieved.

中文翻译：

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微通道中液滴的形成和变形

摘要

在狭窄的水平微通道中以高度为50至150μm的矩形横截面对液滴的形成规律进行了实验研究。结果表明，当垂直液体桥形式的液滴沿微通道移动时，存在一种新的流动方式。形成这种液滴的三种机理被区分：直接在液体喷嘴附近形成液滴，液滴离开在通道的侧面移动的液体偏离以及由于严重变形的液滴和水平液桥的破坏而形成的液滴。已经确定，液滴的变形随着韦伯数的增加而增加。已经证明，当达到韦伯数的第一个临界值时，液滴开始变形，而当达到第二个临界值时，液滴开始被破坏。