In this work, we used a coupled level set and volume of fluid (CLSVOF) computational method for studying the generation of microdroplets in a two-dimensional circular coflow microfluidic device. The fundamental understanding of shear-thinning behavior on controlled droplet formation in a microchannel is systematically investigated. Droplet generation and dynamics are controlled by altering the operating conditions and fluid properties, such as CMC solution concentration, both fluids’ flow rates, and interfacial tension. The droplet length, velocity, liquid film thickness, and formation frequency are quantitatively analyzed and presented in a non-dimensional form. The droplet length decreased with the flow rate and concentration of the CMC solution. However, the length of the droplet increased with the dispersed phase flow rate and interfacial tension. From the set of simulation data, flow regime maps and scaling relations are developed over a range of operating conditions. This work provides critical insights into the uniform and controlled droplet formation in shear-thinning fluids within a circular coflow microchannel, offering guidance for future innovations in the design and optimization of microfluidic systems for specific applications.

中文翻译：

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Coflow 微流控装置中被剪切稀化流体包围的受控液滴形成的数值分析


在这项工作中，我们使用耦合水平集和流体体积 （CLSVOF） 计算方法来研究二维圆形共流微流体装置中微液滴的产生。系统地研究了微通道中受控液滴形成的剪切稀化行为的基本理解。通过改变操作条件和流体特性（例如 CMC 溶液浓度、流体的流速和界面张力）来控制液滴的产生和动力学。对液滴长度、速度、液膜厚度和形成频率进行定量分析，并以无量纲形式表示。液滴长度随 CMC 溶液流速和浓度的增加而减小。然而，液滴的长度随着分散相流速和界面张力的增加而增加。根据模拟数据集，在一系列操作条件下开发流态图和缩放关系。这项工作为圆形 coflow 微通道内剪切稀化流体中均匀和受控的液滴形成提供了重要见解，为未来针对特定应用的微流体系统设计和优化的创新提供了指导。