Part II. Swarm of bubbles in a power law fluid

Abstract

The Sherwood number and the drag coefficient for a swarm of bubbles moving in a power law fluid are obtained by an approximate solution of equations of motion in the creeping flow regime. The effect of gas holdup on the motion and mass transfer of a swarm of bubbles with a mobile interface moving in a power law fluid was obtained using Happel's free surface cell model. Since the presence of surfactants may cause small bubbles to behave as solid spheres, expressions for Sherwood number and drag coefficient are also obtained by using the results of power-law fluid motion over assemblages of solid spheres. It is predicted that, unlike the case of a single bubble, the drag coefficient correction factor and the mass transfer correction factor decrease with increasing pseudoplasticity.