Reconnection of orthogonal cylindrical vortices

This paper reports on a numerical study of the interaction of a pair of orthogonal cylindrical vortices. The vortices have equal radii and vorticity distributions, which are chosen to be either uniform or parabolic, and are initially located at various distances. A vortex-in-cell model simulates the flow evolution in a triply periodic cube; the model contains no viscous terms but it introduces a small numerical viscosity (equivalent to Re>15000). It was found that the time at which the reconnection starts significantly increased with the initial distance between the vortices; in contrast, the reconnection lasted approximately 3/4 of the eddy turnover time for all initial distances and the two vorticity profiles considered in this study. This confirms that the reconnection is a convective process made possible by even the weakest viscosity.