Spectrum of Kelvin-wave turbulence in superfluids

Kelvin-wave turbulence in superfluids

Differential approximation for Kelvin-wave turbulence

I present a nonlinear differential equation model for the spectrum of Kelvin waves on a thin vortex filament. This model preserves the original scaling of the six-wave kinetic equation, its direct and inverse cascade solutions, as well as the thermodynamic equilibrium spectra. 1 Kelvulence: cascades and spectra. Kelvin waves propagating on a thin vortex filament were proposed by Svistunov to be...

Kelvin-wave turbulence generated by vortex reconnections

Reconnections of quantum vortex filaments create sharp bends which degenerate into propagating Kelvin waves. These waves cascade their energy down-scale and their waveaction up-scale via weakly nonlinear interactions, and this is the main mechanism of turbulence at the scales less than the inter-vortex distance. In case of an idealised forcing concentrated around a single scale k0, the turbulen...

On Kelvin-Helmholtz instability in superfluids

The Kelvin-Helmholtz instability in superfluids is discussed, based on the first experimental observation of such instability at the interface between superfluid He-A and superfluid He-B [1]. We discuss why the Kelvin-Helmholtz criterion, the Landau critical velocity for nucleation of ripplons, and the free energy consideration all give different values for the instability treshold. 1 Classical...

Wave-number spectrum of drift-wave turbulence.

A simple model for the evolution of turbulence fluctuation spectra, which includes neighboring interactions leading to the usual dual cascade as well as disparate scale interactions corresponding to refraction by large scale structures, is derived. The model recovers the usual Kraichnan-Kolmogorov picture in the case of exclusively local interactions and midrange drive. On the other hand, when ...