An apparatus to study the vortex ring structure generated by a bursting bubble

摘要

An apparatus is described that facilitates the first detailed photographic study of the vortex ring structure created by a bursting bubble resting on a pool of liquid. The discovery of a novel method of bubble positioning was essential to success. A shallow liquid pool is formed by the convex meniscus on the flat top of a vertically oriented cylinder, on which a single bubble will centre itself. An aerosol is used to inflate the bubble and act as a flow-visualization medium. A spark ruptures the bubble and triggers the photographic process, generating a time-delayed sequence of photographs to study the retraction of the bubble film and the evolution and speed of the resulting vortex ring structure. The in situ surface tension of the centred bubble film can be calculated using Laplace's equation and the measured bubble pressure.