Quantitative study of the production rate of droplets in a T-junction microdroplet generator

In a T-junction microdroplet generator, a mathematical model which can quantify the production rate of droplets is demonstrated. The experiments of droplet formation are performed for different geometries of the T-junction microchannels, and good agreements are shown between the predicted and the measured values of the droplet production rates. From both theoretical and experimental study, the production rate of droplets varies nonlinearly with the flow-rate ratio of the two phases during droplet formation, and by fixing the flow-rate ratio, the production rate of droplets is approximately a linear function of the flow rate of the fluids. In particular, the coefficients of the linear relation are only determined by the geometrical parameters of the T-junction microchannel. As a result, our model can be validated experimentally, and especially for a specific geometry of the T-junction, the production rate of droplets can be precisely predicted and controlled based on the flow rate of the fluids.