Succession of Resonances to Achieve Internal Wave Turbulence

Géraldine Davis (1) , Timothée Jamin (1) , Julie Deleuze (1) , Sylvain Joubaud , Thierry Dauxois

1 Phys-ENS - Laboratoire de Physique de l'ENS Lyon

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.

Domaines: Dynamique des Fluides [physics.flu-dyn]

Géraldine Davis, Timothée Jamin, Julie Deleuze, Sylvain Joubaud, Thierry Dauxois. Succession of Resonances to Achieve Internal Wave Turbulence. Physical Review Letters, 2020, 124, ⟨10.1103/physrevlett.124.204502⟩. ⟨hal-02994113⟩