Formation of Vortex Rings from a Liquid Drop

Abstract

A DROP of liquid heavier than water, for example blue or red ink, submerged quietly into still water, encounters the resistance of the medium and becomes flatter in its form in the course of its descending motion. The central part of the disc thus formed soon disappears, and consequently a ring form results. This is a very slowly whirling vortex ring. As it proceeds, the radius of the ring is augmented, and it begins to disintegrate into several minor vortex rings. Each of the secondary vortex rings proceeds in the same manner as the primary one, and disintegrates as well. The process of disintegration may be continued so far as the material remains ample.