This paper presents a parametric study using a three-phase axisymmetric numerical simulation on a dual co-axial microfluidic device for creating compound droplets. The Volume of Fluid-Continuum Surface Force model (VOF-CSF) was developed to perform a parametric analysis of the double emulsion formation in a dual co-axial microfluidic device. The model was used to investigate the effects of phase velocities, viscosities, and interfacial tensions on the size and generation rate of the double emulsions, with the assistance of the Design of Experiments (DOE) and Response Surface Methodology (RSM). The DOE considerably decreased the number of simulations. A sensitive analysis revealed that the outer phase parameters have the most noteworthy influence on double emulsion characteristics. Dimensionless numbers, including Weber number of the inner phase (We_in), the capillary number of the middle phase (Ca_mid), and the capillary number of the outer phase (Ca_out), were also implemented to examine the effects of essential forces on the double emulsion size. The simulation results verified that the size of both the inner and the outer droplets could be easily adapted within a broad range by adjusting non-dimensional parameters. The simulation results can be utilized to generate a broad range of liquid-liquid encapsulated structures.

本文介绍了在双同轴微流控装置上使用三相轴对称数值模拟创建复合液滴的参数化研究。开发了流体连续体表面力模型（VOF-CSF），以对双同轴微流控设备中的双乳化液形成进行参数分析。在实验设计（DOE）和响应表面方法（RSM）的帮助下，该模型用于研究相速度，粘度和界面张力对双重乳液尺寸和生成速率的影响。DOE大大减少了仿真次数。敏感的分析表明，外相参数对双重乳液特性的影响最大。无量纲数，包括内相的韦伯数（我们_在）中，还采用了中间相的毛细管数（Ca _mid）和外部相的毛细管数（Ca _out），以检查基本力对双倍乳液尺寸的影响。仿真结果证明，通过调整无量纲参数，内部和外部液滴的大小都可以轻松地在很宽的范围内进行调整。仿真结果可用于生成广泛的液-液封装结构。