Cantero et al. supplementary movie
Movie 1. This movie shows a density current that develops from the collapse of a cylinder of heavy fluid in a lighter environment. The flow is computed by direct numerical simulation in a square domain with dimensions 15Hx15HxH and with grid resolution of 880x880x180. The Reynolds number of the flow is Re=8950. Initially the flow evolves nearly axisymmetrically, in which Kelvin-Helmholtz rings develop and form along the front and body of the current. As a consequence of the no-slip condition at the bottom, the current presents a lifted nose and a layer of light fluid penetrates below the front, producing a region of unstable stratification. Incipient lobes and clefts start to form at the leading edge soon after the collapse and evolve into a mature pattern that shows several mergers and splitings of lobes. As the front advances, the Kelvin-Helmholtz rings destabilize and eventually decay into smaller scale turbulence (see also movie 3). This complex dynamics of the vortex rings is controlled by a delicate balance between baroclinic production, stretching, tilting, transport and dissipation. This movie was produced by David Bock at the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign by volumetric rendering of the density field.
Journal of Fluid Mechanics,
Volume 590 /
, Published online: 15 October 2007