Microdroplet coalescences at microchannel junctions with different collision angles
Microdroplet coalescences at microchannel junctions with different collision angles
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DOI：
10.1002/aic.13825
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发表时间：
2013-02
期刊：
影响因子：
3.7
通讯作者：
Kai Wang;Yangcheng Lu;Lu Yang;G. Luo
中科院分区：
文献类型：
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作者：
Kai Wang;Yangcheng Lu;Lu Yang;G. Luo
微液滴的聚并机理对于微结构多相化工过程的小型化具有重要意义。采用三种不同物性的工作系统，对不同微通道连接处微液滴聚并的流体动力学进行了实验研究。研究了区分微滴聚结与非聚结的临界毛细管数，并以膜排水时间和液滴接触时间为重要参数，分析了临界毛细管数随液滴尺寸、碰撞角和物理性质的变化规律。实验结果表明，减小液滴碰撞角可以促进液滴的聚并。通过对临界毛细数的分析，比较了受限微通道和自由流动空间中微液滴聚并过程的差异。提出了一个预测临界毛细数的模型方程，为新型微结构化学器件的设计和开发提供了有价值的信息。© 2012美国化学工程师学会AIChE J，59：643-649，2013
Microdroplet coalescence mechanism is very important for the miniaturization of multiphase chemical processes with microstructured devices. Using three working systems with different physical properties, this article presents an experimental study on the fluid dynamics of microdroplet coalescence at different microchannel junctions. The critical capillary number to distinguish coalescence or noncoalescence of microdroplet is investigated and its variations with droplet size, collision angle, and physical properties are analyzed with two important parameters – the film drainage time and droplet contact time. Experimental results indicate that microdroplet coalescence can be enhanced by reducing the droplet collision angle. The differences of microdroplet coalescences in confined microchannels and free-flowing spaces are provided with the analysis of critical capillary number. A model equation is proposed to predict the critical capillary numbers in this study, which may provide valuable information for the design and development of new microstructured chemical device. © 2012 American Institute of Chemical Engineers AIChE J, 59: 643–649, 2013