Interface‐shrinkage‐driven breakup of droplets in microdevices with different dispersed fluid channel shape |
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| Authors: | Wenjie Lan Zhihui Wang Yinjie Du Xuqiang Guo Shaowei Li |
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| Affiliation: | 1. State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China;2. Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China;3. State Key Laboratory of Chemical Engineering, Tsinghua University, Beijing 100084, China |
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| Abstract: | A new droplet breakup mechanism is previously proposed—interface‐shrinkage‐driven breakup. In coaxial microdevices, when the contact angle between the continuous phase and dispersed fluid channel (DFC) is sufficiently low, the new mechanism instead of the classic shear‐driven mechanism dominates the breakup. The present study further investigated the new mechanism in microdevices with DFCs of different shape. Critical contact angles in different devices were determined by theoretical analysis and verified by experiments. It was found that the critical contact angle for the new mechanism depends on the shape of the DFC. The droplet size was measured for different devices when the new mechanism dominated the breakup. In contrast to the case for the shear‐driven mechanism, the droplet size is little affected by the capillary number. Mathematical models were established to predict the droplet size in different devices and results were found to agree well with experimental results. © 2017 American Institute of Chemical Engineers AIChE J, 63: 367–375, 2018 |
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| Keywords: | droplet breakup microfluidic device contact angle droplet size |
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