Oscillatory modes of concentration convection

Experimental studies of oscillatory regimes of Marangoni concentration (solutal) convection, which are due to competition between the capillary and gravitational mechanisms of motion in two-phase fluid systems, are reviewed. Application of optical methods enables advancement from a qualitative description of phenomena to quantitative measurements; it also makes it possible to determine the oscillation period and duration of the oscillatory mode as functions of the features of the concentration distribution of surfactants, physicochemical properties of contacting fluids and the surfactants employed, and the surface activity of the surfactants. The development of oscillatory flow regimes in the vicinity of bubbles and drops in vertical and horizontal layers and near vertical phase interfaces is analyzed.