Scattering and Leapfrogging of Vortex Rings in Superfluids
on February 22, 2017 from 6:30 PM to 8:00 PM
Professor Ricardo Carretero , SDSU Dept of Mathematics and Statistics
Hosted bY IEEE COMPUTATIONAL INTELLIGENCE, PHOTONICS, AND COMPUTER SOCIETIES
In this talk we will explore the beautiful and complex world of vortex rings. A vortex ring is formed when a vortex line (a "twister") is looped back onto itself creating a close ring that carries vorticity. In the first part of the presentation, we will showcase how vortex rings are commonplace in a wide range of fluids. For example, in liquids, many species of marine mammals know how to create them, play with them and even use them to catch prey! Smoke rings in gases are also common. In fact not only people can make smoke rings, but volcanoes and chimneys are also at it!
In the second part of the presentation, we will focus on the occurrence of vortex rings in superfluids (fluids without viscosity). We will specifically focus on the realm of the nonlinear Schroedinger equation which serves as an accurate model for the meanfield dynamics of Bose-Einstein condensates. We showcase some of the basic vortex ring phenomenology including, internal excitation waves (Kelvin modes), their mutual interactions, collisions, and scattering scenarios. We also briefly discuss an efficient computational implementation for solving the ensuing partial differential equations using GPU accelerated codes that allow for numerical integration runs of vortex rings (almost) in real time!