Droplet and bubble dispersion in step T-junction microchannel

CHEN Yuchao1 CUI Yongjin1 WANG Kai1 LUO Guangsheng1

(1.Department of Chemical Engineering, State Key Laboratory of Chemical Engineering, Tsinghua University, Beijing, China 100084)

【Abstract】A high-speed camera was used to study the dispersion of droplets and bubbles in a stepped T-junction microchannel embedded in a capillary. The effects of two-phase flow, viscosity, and surfactant on the flow pattern and the size of droplets and bubbles were investigated. The results show that for the droplet dispersion system, the flow pattern is determined by the concentration of the surfactant and the continuous-phase flow rate. The flow pattern changes from dripping flow to jetting flow as the two factors increase. For the bubble dispersion system, only the squeezing and dripping flow patterns exist. Addition of the surfactant has almost no effect on the bubble dispersion. The droplet and bubble size can be much smaller than the channel size. The mathematical models for predicting the dispersion size in different systems are established, and the models have good prediction performance.

【Keywords】 microchannels; microfluidics; multiphase flow; microdispersion; flow pattern;


【Funds】 National Key Research and Development Program of China (2017YFB0307102) National Natural Science Foundation of China (91334201)

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(Translated by WANG YX)


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This Article


CN: 11-1946/TQ

Vol 71, No. 01, Pages 265-273

January 2020


Article Outline


  • Introduction
  • 1 Experimental materials and methods
  • 2 Experimental results and discussion
  • 3 Conclusion
  • References