Early observations and experiments on ring vortices

This paper discusses the observation and study of ring vortices from their first appearances in English literature and Dutch painting in the early 1600s to the publication of Helmholtz's seminal paper on vortex motion in 1858. In this period ring vortices were observed primarily when produced by tobacco smokers, volcanic exhalations, and bursting bubbles of phosphine. This review shows that eminent scientist such as Michael Faraday and Charles Babbage experimented with ring vortices in the first half of the 1800s. Even more noteworthy, however, are the experiments of Rudolph Meyer on the interaction of two nearby vortices moving in the same direction and the experiments of Ernesto Capocci on the formation of the ring vortex. In 1829 Meyer observed that when the rings move parallel to each other they break up and reconnect to form a single one, and when they move in tandem the front vortex expands and the rear one passes through it. In 1845 Capocci explained the ring formation with a qualitative version of what is now known as the slug-flow model. These three subjects became active areas of research only in the last decades of the twentieth century. (C) 2013 Elsevier Masson SAS. All rights reserved.