Interfacial turbulence in minute drops evaporating on a flat plate

Abstract

Surface tension/temperature driven interfacial turbulence in evaporating minute drops was studied photographyically using the laser shadowgraphy. Liquids of relatively low boiling point were employed: ethyl ether, acetone, methanol, carbon tetrachloride, benzene and heptane. A drop surface on a glass plate at room temperature was photographed straight down with motion picture. During drop lifetime, the interface exhibited a dominant pattern of radial stripes over a very brief duration followed by polygonal cells and ended in ripples. These interfacial forms are related to three stages of drop evaporation. The mechanism of interfacial turbulence is proposed.