Abstract
A row of vortex rings, which consists of vortex rings at a fixed frequency from a circular orifice, was photographed by a 16 mm cine-camera using the smoke visualization method to study phenomena of the interaction among ring vortices in the vortex row.
The interaction phenomena, observed with increase in velocity at the orifice exit at a constant, vortex generating frequency, were classified into the following four modes ;weak vortex group interaction mode, irregular merging mode, merging mode and passing-through mode. Another interaction phenomenon, which was named as frozen interaction mode, appeared at the same exit velocity as that for merging mode or passing-through mode and at a frequency decreased to a half of that for the two modes.
The first merging or passing-through of two successive vortex rings occurs within the distance nearly one orifice diameter. A kind of feed-back mechanism was proposed to explain the jittering of the location.
