Author(s)

R. Bel Fdhila & P.C. Duineveld

Abstract

Axisymmetric steady flow calculation around a bubble through quiescent liquid containing surface active impurities R. Bel Fdhila, P.C. Duineveld University ofTwente, Department of Mechanical Engineering Netherlands abstract In this work we study the effect of surfactants on the motion of air bubbles rising in water at high Reynolds number. We consider surfactants having a desorption rate much slower than the convective rate. Surfactant molecules collect at the rear part of the bubble, forming a stag- nant cap where the no-slip condition at the interface holds. The boundary-value problem associated with the mixed boundary conditions at the bubble surface is studied numerically by solving the complete Navier-Stokes equations describ- ing the axisymmetric flow around the bubble, using a vorticity-stream function formulation. The finite difference method, based on Alternating Directions Implicit (ADI), is used to solve the basic set of equations and gives a complete discription of th

Keywords