The Emergence of Small Scales in Vortex Ring Collisions

The Emergence of Small Scales in Vortex Ring Collisions Ryan McKeown, Harvard University Rodolfo Ostilla Monico, Harvard University Alain Pumir, ENS Lyon Michael P. Brenner, Harvard University Shmuel M. Rubinstein, Harvard University DOI: When two coherent vortex rings collide head-on, they explode into a turbulent cloud. This video investigates how the rapid generation of these small-scale flow structures is mediated by the interactions of the two colliding vortex cores. We observe a novel mechanism by which the vortex cores are flattened into sheets and break down into smaller secondary vortices, which, themselves break down into even smaller tertiary vortex filaments. This iterative cascade is a possible mechanism by which fine-scale flow structures emerge in turbulent flows. See other videos from the 2017 Gallery of Fluid Motion: