Visualization of Media Contact Areas in Drop Impact Flows with Chemical Reactions

Abstract

For the first time, the process of merging a drop of ferric chloride solution (concentration 16 and 1%) with a solution of ammonium thiocyanate (20%), including the formation and restructuring of a system of inclined loops on the surface of the cavity, visualized by the products of a chemical reaction, was recorded on video. The brightly colored iron thiocyanate solution formed during the merging of liquids lands into primary contact droplets and groups of subsequent splashes. Fibers containing iron thiocyanate form linear and mesh structures on the walls of the cavity and crown. Ledges and small annular legged vortices are formed at the bottom of the cavity, under the mesh nodes. During the cavity collapse, the ledges extend into inclined loops up to 4.6 mm long, which penetrate into the target fluid. As the flow evolves, the fibers rearrange, forming new structures. Finely colored areas persist for a long time and spread out under the influence of diffusion processes.