Head-on Collisions of Vortex Rings with Solid Bodies

The head-on collision of vortex rings with slender wires creates complex vortex reconnection and breakdown behavior. Specifically, the interaction results in the rapid emergence of secondary vortical structures. These structures suggest that vortex lines are being created in the fluid; however, as, in the finite Reynolds number regime, vorticity must either close in on itself or begin or end on a boundary, the origin of the secondary structures is not well understood. We experimentally investigate the emergence and evolution of this behavior by varying the vortex ring dyeing technique, geometry of the wire, and Reynolds number. This allows us to characterize the interaction of the vortex core with the secondary vortical structures.