The tripole: A new coherent vortex structure of incompressible two-dimensional flows |
| |
| Authors: | Lorenzo M Polvani Xavier J Carton |
| |
| Institution: | 1. Department of Mathematics , Massachusetts Institute of Technology , Cambridge, MA, 02139, U.S.A.;2. Center for Meteorology and Physical Oceanography , Massachusetts Institute of Technology , Cambridge, MA, 02139, U.S.A. |
| |
| Abstract: | Abstract Using a contour dynamical algorithm, we have found rotating tripolar V-state solutions for the inviscid Euler equations in two-dimensions. We have studied their geometry as a function of their physical parameters. Their stability was investigated with the aid of contour surgery, and most of the states were found to be stable. Under finite-amplitude perturbations, tripoles are shown to either fission into two asymmetric dipoles or to evolve into a shielded axisymmetric vortex, demonstrating the existence of two new ‘‘reversible transitions'’ between topologically distinct coherent vortex structures. These dynamical results are confirmed by pseudo-spectral simulations, with which we also show how continuous tripolar long-lived coherent vortex structures can be generated in a variety of ways. |
| |
| Keywords: | Coherent vortices Euler equations |
|
|
