Dynamics of bubble growth and detachment in a viscous shear flow

Abstract

The quasistatic injection of air bubbles at the wall in a viscous shear flow is experimentally investigated by high-speed video pictures and image processing. The bubble radius and center of gravity position are determined throughout the growth. Experimental results are then used to validate a force balance model during bubble growth and after detachment for small bubble Reynolds numbers. The contact angles at the bubble foot calculated from the force balance agree well with those experimentally obtained from image processing. Finally, the force balance model is used to predict the departure bubble radius versus the gas flow rate and liquid flow shear rate.