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DY: Fachverband Dynamik und Statistische Physik

DY 34: Fluid Dynamics and Turbulence II

DY 34.6: Vortrag

Donnerstag, 17. März 2011, 15:30–15:45, ZEU 255

(contribution withdrawn) Vortex-dipole chaos solves last enigma of classical physics: turbulence. — •Helmut Baumert — IAMARIS, Bei den Mühren 69 A, 20457 Hamburg

The talk sketches a statistical quasi-particle approach to idealized fluid turbulence at asymptotically high Reynolds numbers, based on an ensemble of dipole vortex tubes realized in geometrically non-trivial forms like rings etc. In a cross sectional area through a vortex tangle, taken locally orthogonal through each individual tube, the dipoles are moving with the classical dipole velocity. The effective vortex radius is related with Prandtl's classical mixing length.

A quasi-particle is dressed, embedded in a cloud of others. Its energy is finite. It performs a local quasi-2D dipole chaos, reminding of real gases. Collisions between stable quasi-particles lead either to scattering (turbulent diffusion) or to particle annihilation (formation of unstable couples as stationary dissipative patches via the "devil's gear" of Herrmann, 1990, down to a scale of size zero).

This geometrization allows to derive equations of turbulent motions and of fundamental constants like von Karman's or two Kolmogorov spectral constants - in agreement with observations. In particular, it allows a better understanding of stratified flows (collapsing turbulence, whitecapping of internal gravity waves).

This work relates to Department of the Navy Grant N62909-10-1-7050 issued by Office of Naval Research Global. The talk will be given in German.