Experimental study of the interaction of thermals

A photographic technique was used to study the interaction of two thermals appearing as the result of the ascent of spherical pockets of gas which are lighter than the ambient medium. In the process of ascent, such thermals are transformed into vortex rings, with the lighter gas being transformed into toroidal cores. Interaction processes at various stages of this transformation are examined. The existence of three regimes of interaction is shown: mergence into one rising vortex ring, mutual repulsion, and mutual destruction.