Interaction between buoyant and solutocapillary convections induced by a surface-active source placed under the free surface

Abstract

The onset and stability of solutal (buoyancy and Marangoni) convection induced by a localized source of surface-active substance placed under an interface were studied both experimentally and theoretically. It was shown that the competition between the buoyancy and solutocapillary convection can lead to the onset of oscillatory convection. The period of the observed oscillations appreciably depends on the relation of Grashof and Marangoni numbers and on the aspect ratio of the geometrical sizes of the problem. It was found out that an increase of the buoyancy contribution leads to the onset of stationary convection instead of oscillatory one.