Dynamics of the Floating-Up of a Bubble Cluster

Results of experimental investigation of the floating-up of a cluster of air bubbles in a viscous fluid by an optical method are presented. A setup has been developed for formation of a compact cluster of monodisperse bubbles with assigned diameter and volume concentration. It is shown that the velocity of the floating-up of a cluster of bubbles is higher than the velocity of the floating-up of a single bubble and depends on their number, diameter, and the distance between the bubbles. An empirical dependence of the resistance coefficient of a cluster of air bubbles floating up in glycerin on the Reynolds number has been obtained.