Generation of intermittent gravitocapillary waves via parametric forcing

TL;DR

This paper investigates the generation of intermittent gravitocapillary waves through parametric forcing, revealing a power-law spectrum and scale-invariant intermittency linked to Faraday wave breakup and advection by gravity waves.

Contribution

It demonstrates the emergence of intermittent wave fields with scale-invariant properties driven by Faraday wave interactions and advection, providing new insights into wave turbulence phenomena.

Findings

Power-law frequency spectrum of surface wave fluctuations

Strong variation in height increment PDFs across time scales

Nonlinear exponents in structure function power laws

Abstract

We report on the generation of an intermittent wave field driven by a horizontally moving wave maker interacting with Faraday waves. The spectrum of the local gravitocapillary surface wave fluctuations displays a power law in frequency for a wide range of forcing parameters. We compute the probability density function of the local surface height increments, which show that they change strongly across time scales. The structure functions of these increments are shown to display power laws as a function of the time lag, with exponents that are nonlinear functions of the order of the structure function. We argue that the origin of this scale-invariant intermittent spectrum is the Faraday wave pattern breakup due to its advection by the propagating gravity waves. Finally, some interpretations are proposed to explain the appearance of this intermittent spectrum.