Effect of channel width on droplet generation inside T-junction microchannel

Abstract

In a T-junction microchannel, channel geometry plays a major role that affects the physics behind droplet generation. The effect of channel width on droplet size and frequency in a T-junction microchannel is investigated in the present study. The current work is an extension of our previous work, where a model was developed to predict the size of the droplets generated in a T-junction microchannel when both the continuous and dispersed phase channels have equal widths. In the present work, we extended the model to account for the varying width ratio between the dispersed and continuous phase channels. We performed in-house experiments by varying the channel width and viscosity ratios between the fluids to study the size of the droplets generated and to validate the proposed scaling law. We further investigated the effect of channel geometry on the frequency of droplet generation in the T-junction microchannels. The experimental results show that the droplet length increases with an increase in the width of the continuous phase channel. On the other hand, the droplet production frequency decreases with an increase in the width of the continuous phase channel. With variations in the width of the dispersed phase channel, similar behavior in droplet sizes and the frequency of droplet production is observed. The analysis of this study provides new insight into the effect of channel width on the droplet length and frequency. Overall, this research intends to provide a thorough understanding of the design of microchannels based on the geometry and manipulation of droplets with varying widths.