Internal Circulations within Liquid Drops

Abstract

IT has long been recognized that under certain conditions some sort of axisymmetric flow is induced within liquid drops as they pass through a viscous medium. The factors which promote and inhibit such internal circulations have been established experimentally for liquid-liquid systems, but there is little or no direct evidence that comparable vortical flows are formed within water drops falling through the atmosphere. In liquid-liquid systems the pattern of flow is generally mapped on a photographic film by the images of small opaque particles moving with the fluid. Garner and Haycock¹ made some velocity measurements by obtaining such photographs with a carefully calibrated moving-picture camera and noting the change in position of the particle during a known time interval. However, most of the velocity data have been inferred from terminal velocity measurements and rates of heat and mass transfer between the drop and continuous phases.