Response of a columnar vortex to a wrapped vortex loop

Iowa Institute of Hydraulic Research and Department of Mechanical Engineering, The University of Iowa Iowa City, Iowa, U.S.A

Abstract

A computational and experimental study of the interaction between an initially columnar vortex and a wrapped vortex loop was performed, which focused on the columnar vortex response to the vortex loop. This problem is motivated by applications involving three-dimensional vortex interaction with a solid body, where the secondary vorticity shed from the body rolls up into a series of loop-like structures that are advected away from the body by the primary vortex. As a secondary vortex loop wraps around a columnar vortex, it becomes entrained into the vortex core due to the self-induced velocity of the loop. The columnar vortex response as a secondary vortex loop moves close to and impacts upon its lateral core surface includes a combination of bending waves, waves of variable core area, and core shape deformation. If a vortex loop is sufficiently strong, its interaction with the columnar vortex is also accompanied by ejection of vorticity from the columanr vortex, sometimes leading to development of a traveling vortex breakdown.