Quantification of interfacial mass transfer during droplet formation in a microfluidic T-junction using VOF

Abstract

Taylor flow in microchannels is characterized by interfacial mass transfer rates which are two to three orders of magnitude larger than in conventional reactors. During the droplet formation stage vortices are observed which further contribute to interfacial mass transfer. In this work, we quantify the contribution of the droplet formation stage to the overall mass transfer by integrating a compressive continuum species transfer model into a volume-of-fluid (VOF) solver. It is observed that the interfacial mass transfer depends solely on the vortex intensity. Moreover, altering the flow rate ratio and viscosity significantly affects the interfacial mass transfer performance. Overall, the interfacial mass transfer during the droplet formation stage contributes up to ∼70% of the overall mass transfer at large relative velocities between the dispersed and continuous phases. The present findings will guide applications involving interfacial mass transfer in microchannels.