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Numerical Simulation of Droplet Generation in Coaxial Microchannels

Zongjun Yin*, Rong Su, Hui Xu

School of Mechanical Engineering, Anhui Institute of Information Technology, Wuhu, 241100, China

* Corresponding Author: Zongjun Yin. Email: email

Fluid Dynamics & Materials Processing 2024, 20(3), 487-504.


In this study, numerical simulations of the pinching-off phenomena displayed by the dispersed phase in a continuous phase have been conducted using COMSOL Multiphysics (level-set method). Four flow patterns, namely “drop flow”, “jet flow”, “squeeze flow”, and “co-flow”, have been obtained for different flow velocity ratios, channel diameter ratios, density ratios, viscosity ratios, and surface tension. The flow pattern map of two-phase flow in coaxial microchannels has been obtained accordingly, and the associated droplet generation process has been critically discussed considering the related frequency, diameter, and pinch-off length. In particular, it is shown that the larger the flow velocity ratio, the smaller the diameter of generated droplets and the shorter the pinch-off length. The pinch-off length of a droplet is influenced by the channel diameter ratio and density ratio. The changes in viscosity ratio have a negligible influence on the droplet generation pinching frequency. With an increase in surface tension, the frequency of generation and pinch-off length of droplets decrease, but for small surface tension the generation diameter of droplet increases.

Graphical Abstract

Numerical Simulation of Droplet Generation in Coaxial Microchannels


Cite This Article

Yin, Z., Su, R., Xu, H. (2024). Numerical Simulation of Droplet Generation in Coaxial Microchannels. FDMP-Fluid Dynamics & Materials Processing, 20(3), 487–504.

cc This work is licensed under a Creative Commons Attribution 4.0 International License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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