Computational Prediction of Capillary Number Impact on Droplets Formation in Microchannels

The present microfluidic study is emphasizing the flow behavior of two immiscible fluids within a Y shape micro-bifurcation with two inlets and one outlet. We report here a numerical investigation on the interface shape dynamics manifested at different capillary numbers (Ca), by a variation of the flow rate ratios (FRR) over the inlets. The numerical flow patterns are found to be in good agreement with the experimental manifestations. We demonstrated numerically that the Ca variation has an important impact on the droplet frequency formation. Changing only the FRR of the inlets, the droplets behavior modifies drastically. From the numerical point of view, the interface shape is used to characterize the manifestation of droplet formation.