Bubble formation in a step-emulsification microdevice with parallel microchannels

被引:12
作者
Zhang Z. [1 ]
Jiang S. [2 ]
Zhu C. [1 ]
Ma Y. [1 ]
Fu T. [1 ]
机构
[1] State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin
[2] The 718th Research Institute of China Shipbuilding Industry Corporation, No. 17 Zhanlan Road, Handan, 056027, Hebei
基金
中国国家自然科学基金;
关键词
Bubble; Interfacial phenomenon; Microfluidics; Numbering-up; Step-emulsification;
D O I
10.1016/j.ces.2020.115815
中图分类号
学科分类号
摘要
In this paper, the mechanism of bubble generation in a step-type microdevice with 10 parallel microchannels is studied by using a high-speed camera. The evolution of the gas–liquid interface during bubble formation is explored. It is found that the evolution of the gas–liquid interface is controlled by the inertial force, viscous shear stress, liquid pressure difference, and the Laplace pressure. The second expansion stage of the head distance of the gaseous thread is the key to determine the bubble size. The size of bubbles depends on the physical properties of the fluids, which is different from the results for droplets. A semi-empirical model for predicting bubble's volume is proposed. Finally, a pressure drop model is proposed to understand the mechanism of the multi-microchannel alternating generation mode, and the feedback effect of the bubble behavior in the confined cavity on the generation mode is analyzed. © 2020 Elsevier Ltd
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