MARANGONI INSTABILITY OF 2 LIQUIDS MIXING AT A FREE-SURFACE

The impact of a water drop on a thin layer of glycerin leads to the fo rmation of an intricate flower-like pattern. We show that these leaf-l ike forms are generated by a surface-tension instability at the air-li quid interface along which there exists variable concentration of glyc erin and water. Spatial variations of surface tension drive intense vo rtices inside the water layer, which interact with the glycerin-water concentration at the surface. Horizontal bending of these vortices is reinforced by the resulting enhancement of the surface-tension gradien ts. (C) 1998 American Institute of Physics. [S1070-6631(98)01512-8].