Numerical Study of Droplet Generation Process in a Microfluidic Flow Focusing

Microfluidic flow focusing devices have been utilized for droplet generation on account of its superior control over droplet size. Droplet based microfluidics addressed many scientific issues by providing a novel technological platform for applications such as biology, pharmaceutical industry, biomedical studies and drug delivery. This study numerically investigated the droplet generation process of an aqueous flow in oleic acid oil in a microfluidic flow focusing device. A conservative level set method is conducted to numerically model the droplet generation process. The post processing of the simulation results are done using Canny edge detection image processing method, which is a novel approach. Moreover, the results of the numerical simulation were compared to the experimental data provided by Ten et al. on the same device. This method showed a maximum average deviation from the experimental results of 14.6% and a minimum of 6.96%. Also, by means of altering water and oil flows, the influence of parameters affecting droplet size, which lead to a better understanding of droplet generation phenomenon, was investigated in this study. Therefore, it can be concluded that the flow ratio and capillary number are the two primary parameters that affect droplet size, while capillary number showed more dominance in comparison to flow ratio.