Fluid-dynamic instabilities during mass transfer across the interface between to immiscible liquids

Experiments and simulations were conducted in a vertically oriented Hele-Shaw cell. Buoyancy driven convection, in particular plumes and double diffusive fingering as well as surface tension driven convection in the form of roll cells have been found in the experiments and reproduced numerically. The calculations reveal the mechanism of the enhancement of mass transfer rates in the presence of the instabilities. The model can be used to predict the mass transfer for the simple geometry of a flat surface.