Succession of Resonances to Achieve Internal Wave Turbulence

• Published in: Physical review letters Vol. 124; no. 20; pp. 1 - 204502
• Main Authors: Davis, Géraldine, Jamin, Timothée, Deleuze, Julie, Joubaud, Sylvain, Dauxois, Thierry
• Format: Journal Article
• Language: English
• Published: College Park American Physical Society 22-05-2020
• Subjects: Fluid Dynamics; Fluid flow; Frequency spectrum; Impulse response; Internal waves; Physics; Turbulence; Wave reflection; Wavelengths
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.124.204502

We study experimentally the interaction of nonlinear internal waves in a stratified fluid confined in a trapezoidal tank. The setup has been designed to produce internal wave turbulence from monochromatic and polychromatic forcing through three processes. The first is a linear transfer in wavelength obtained by wave reflection on inclined slopes, leading to an internal wave attractor which has a broad wave number spectrum. Second is the broadbanded time-frequency spectrum of the trapezoidal geometry, as shown by the impulse response of the system. The third one is a nonlinear transfer in frequencies and wave vectors via triadic interactions, which results at large forcing amplitudes in a power law decay of the wave number power spectrum. This first experimental spectrum of internal wave turbulence displays a k−3 behavior.