Formation characteristics of Taylor bubbles in a T-junction microchannel with chemical absorption

Abstract

This study focuses on the effect of chemical absorption on the formation dynamic characteristics and initial length of Taylor bubbles. The temporal evolutions of neck width and length of gaseous thread and initial length with and without chemical absorption were investigated with the Capillary number and Hatta number between 0.0010–0.0073 and 1.8–5.8 respectively. The squeezing regime with typical three stages, expansion, squeezing and pinch off is observed for both two processes. Compared with the non-absorption process, the increase of formation time in the chemical absorption process arises mainly from the expansion stage, and the decrease of initial length is from the necking stage. In addition, the temporal length evolution satisfies the power-law scale with the same exponent but a smaller pre-exponential factor. The correlations of neck width for stage transition and initial length with Hatta number demonstrate the enhancement effect of chemical absorption on bubble formation dynamics and initial length at relatively high chemical reaction rates and long formation time. This study provides insight into the bubble formation mechanism and helps to regulate the bubble initial size with chemical absorption.