Tuesday, November 5, 2013

Vortex Loops, Helical Spring and Hair Vortex

Vorticity in shearing plasma layers as strings of identical helix units smoothly joined at their junctions. We present scaling versions of vortex stretching, breaking and reconnection at high Reynolds number breeding chiral vortex loops as in phase slippage events in superfluids. 

Here we report the creation of isolated trefoil vortex knots and pairs of linked vortex rings in water using a new method of accelerating specially shaped hydrofoils.

We start by analyzing the origin of chirality in simple systems such as the helical spring and hair vortex.

Laser-induced micro-scale vortex rings have been generated on vaporising tantalum surface, and their reconnection was studied in the presence of shock waves on the nanosecond time scale. A rich spectrum of the ring structures was obtained, some of which have been observed for the first time.

Using the multipulse laser-matter interaction with the Co-coated surface, a one-dimensional high-density vortex-filament array has been created. Increasing the number of pulses, the oscillatory strain field causes the cascade of the shape transformations into structures of increasing topological complexity: vortex filaments into ribbons, into ribbon helicoids and tubular-ribbon helicoids, and then into short ribbon structures with the complex Scherk surface being identified.