A lagrangian approach for the vorticity intensification in swirling rings

The Lagrangian approach, adopted in vortex methods for incompressible Euler flows, is reconsidered here as the most appropriate technique to track the dynamical evolution of organized vorticity structures in free space. We analyze in this paper a specific initial condition, the swirling ring with azimuthal perturbations, from which originate vortex dynamics events leading to a localized but strong vorticity intensification. The aim is to understand the possible development of a finite time singularity, in the context of inviscid flows, and its relevance for the study of intermittency, as one of the most challenging aspects of turbulence.