Salt-finger convection generated by thermal and solutal capillary motion in a stratified fluid

Experiments and numerical simulations were performed to study the onset of finger convection in a stratified fluid layer caused by thermal and solutal capillary motion. Experiments were performed in a stratified ethanol-water solution contained in a shallow tank. Capillary motion was generated by a 2°C temperature difference maintained between the sidewalls. It caused the onset of finger convection by bringing relatively warm and solute-rich fluid on top of relatively cooler solute-poor fluid. A two-dimensional numerical simulation at early times prior to the onset of finger convection was carried out. The results clearly show the interactive effects of thermal and solutal capillary motion.