Toroidal vortex rings

An experimental investigation was carried out to study the toroidal vortex rings generated when a dyed water drop comes into contact with a stationary pool of water. A video camera was used to measure the speed and size of the toroidal vortices over their trajectory. Apart from obtaining a more complete picture of the ring generation mechanism and the nature of the ring trajectory a new axial instability has been found. Some qualitative results have also been obtained on interacting drop-generated vortex rings. (Authors