Kolmogorov and Kelvin-Wave Cascades of Superfluid Turbulence at T=0: What is in Between?

TL;DR

This paper investigates the transition from Kolmogorov to Kelvin-wave cascades in superfluid turbulence at zero temperature, identifying intermediate cascades and vortex ring production as key features.

Contribution

It reveals a chain of three intermediate cascades supported by local-induction vortex motion, bridging the Kolmogorov and Kelvin-wave regimes in superfluid turbulence.

Findings

Identification of three distinct intermediate cascades.

Prediction of vortex ring production at inter-vortex scales.

Clarification of the transformation mechanism between cascades.

Abstract

As long as vorticity quantization remains irrelevant for the long-wave physics, superfluid turbulence supports a regime macroscopically identical to the Kolmogorov cascade of a normal liquid. At high enough wavenumbers, the energy flux in the wavelength space is carried by individual Kelvin-wave cascades on separate vortex lines. We analyze the transformation of the Kolmogorov cascade into the Kelvin-wave cascade, revealing a chain of three distinct intermediate cascades, supported by local-induction motion of the vortex lines, and distinguished by specific reconnection mechanisms. The most prominent qualitative feature predicted is unavoidable production of vortex rings of the size of the order of inter-vortex distance.