Formation of Large-Amplitude Low-Frequency Waves in Capillary Turbulence on Superfluid He-II

TL;DR

This paper investigates how large-amplitude low-frequency waves form in capillary turbulence on superfluid helium, combining experimental and theoretical approaches to reveal their generation alongside the main turbulence cascade.

Contribution

It provides new insights into the simultaneous formation of low-frequency waves and the cascade process in superfluid helium capillary turbulence, considering damping and spectral discreteness effects.

Findings

Low-frequency waves are generated during capillary turbulence.

The study demonstrates the coexistence of low-frequency waves with the Kolmogorov-Zakharov cascade.

Effects of damping and spectral discreteness influence wave formation.

Abstract

The results of experimental and theoretical studies of the parametric decay instability of capillary waves on the surface of superfluid helium He-II are reported. It is demonstrated that in a system of turbulent capillary waves low-frequency waves are generated along with the direct Kolmogorov-Zakharov cascade of capillary turbulence. The effects of low-frequency damping and the discreteness of the wave spectrum are discussed.