Shadowgraph Visualization of Turbulent Exchange between a Vortex Ring and the Environment at Different Densities of the Fluid in the Vortex Interior and Exterior

The turbulent exchange between a vortex ring and the environment was observed using shadowgraph imaging of the process when the density of the fluid inside and outside of the vortex is different. The characteristic distance of turbulent exchange traversed by the vortex is determined, and the dependence of this distance on the vortex velocity and the related Reynolds number is established.