Video Galerie-english

By Adam Fincham Direct Laboratory Simulation (DLS) is a state of the art 3D measurement technique developed at the coriolis laboratory. Using high speed digital cameras synchronized to an opto-mechanical laser scanning assembly, the particle seeded flow is rapidly sampled at up to 100 different levels, the sampling operation is repeated a short time later, and the resulting image data cube pair is subsequently interrogated (online) to generate the 3D velocity and vorticity fields. This technique allows full time resolved Laboratory Simulations of moderate Reynolds number flows under conditions that are inaccessible to current Direct Numerical methods.
441 KB	3D time resolved measurements of the vorticity field in the near wake of a vertical flat plate in a linearly stratified fluid, Re=500, Fr=0.04. This visualization shows the vertical component of vorticity, the development of a vertical wavenumber zig-zag instability locks the vorticies into position with each other, the vorticies then grow in time but remain in phase with each other.
492 KB	3D time resolved measurements of the vorticity field in the near wake of a vertical flat plate in a linearly stratified fluid, Re=1000, Fr=0.1. This visualization shows the vertical component of vorticity. Here the strong inertia associated with the vorticies is sufficient to break the vertical coherence and the vorticies interact at will in layers whose vertical wave number is set by the initial Froude number.
388 KB	3D time resolved measurements of the vorticity field in the near wake of a vertical flat plate in a linearly stratified rotating fluid, Re=500, Fr=0.04, Ro=2. This visualization shows the vertical component of vorticity, the development of the zig-zag instability is inhibited by the background rotation that tends to recolumerize the vorticies. With the preferred positioning broken the flow dissipated much more quickly than in the non-rotating case.
207 KB	3D time resolved measurements of an anticyclonic lens-like vortex (Meddie) generated by vertical mid-depth injection of intermediate density fluid into a linearly stratified rotating tank. The blue indicates the anticyclonic vorticity while the red indicates a cyclonic anulus that encircles the anticyclone. Careful examination will show the presence of a cyclonic vortex (the red leg that extends down from the anulus) that has an associated anticyclonic anulus at depth. The two structures co-rotate around one another forming a baroclinic dipole, and hence providing a self propulsion mechanism for this anticyclonic lens.
1235 KB	3D time resolved measurements of a dipolar eddie in a linearly stratified rotating fluid. The dipole in generated by an injection from a horizontal jet. Some cyclonic vorticity (red) is quickly shed creating an asymmetry that allows the dipole to propagate in a circle corresponding to its Rossby deformation radius.
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