Occurrence Condition of Vortex Reconnection

Abstract

The vortex reconnection is one of the vortex interaction phenomena occurring in turbulent flows. In this numerical study, we focused on the hairpin structure, which played an important role in the reconnection process, and explored the occurrence condition of the hairpin. As a model equation, the extended-type nonlinear Schrödinger equation was considered. As a result, it was found that each term of the extended-type nonlinear Schrödinger equation became zero, at the location and time of hairpin occurrence. This occurrence condition of hairpin could be regarded as the occurrence condition of vortex reconnection, and also as the local and direct occurrence condition of turbulence.