Spatio-temporal detection of Kelvin waves in quantum turbulence simulations

TL;DR

This paper provides evidence of Kelvin waves in quantum turbulence simulations by analyzing high-resolution space-time spectra, revealing their role in energy transfer within superfluid turbulence.

Contribution

It introduces a method to identify Kelvin waves in quantum turbulence simulations using space-time resolved spectra, enhancing understanding of their dynamics and energy transfer mechanisms.

Findings

Kelvin waves are clearly identified in the spectra.

Kelvin waves contribute to energy transfer in quantum turbulence.

High-resolution spectra enable detailed analysis of wave dynamics.

Abstract

We present evidence of Kelvin excitations in space-time resolved spectra of numerical simulations of quantum turbulence. Kelvin waves are transverse and circularly polarized waves that propagate along quantized vortices, for which the restitutive force is the tension of the vortex line, and which play an important role in theories of superfluid turbulence. We use the Gross-Pitaevskii equation to model quantum flows, letting an initial array of well-organized vortices develop into a turbulent bundle of intertwined vortex filaments. By achieving high spatial and temporal resolution we are able to calculate space-time resolved mass density and kinetic energy spectra. Evidence of Kelvin and sound waves is clear in both spectra. Identification of the waves allows us to extract the spatial spectrum of Kelvin waves, clarifying their role in the transfer of energy