Interaction of Two Vortex Rings along Parallel Axes in Air

Abstract

Experimental studies were carried out on the interaction of two vortex rings moving in air side by side along their parallel axes. The behavior of two rings was observed by a flow visualization method and the three-dimensional structure of the cross-linking of the two vortex filaments was studied. This phenomena were classified into three patterns, depending on the initial speeds of two rings. (1) At lower speed, two rings merge into one distorted ring. (2) At higher speed, it splits into two rings again after merging, (3) At still higher speed, they merge, split and merge again into one ring before they diffuse away. Theory of virtual momentum was examined in the case of this interaction of two vortex rings.