Tangential oscillations of a disk in a stratified fluid

Sylvain Joubaud (1) , Bruno Voisin (2) , Thierry Dauxois (1)

1 Phys-ENS - Laboratoire de Physique de l'ENS Lyon
2 LEGI - Laboratoire des Écoulements Géophysiques et Industriels [Grenoble]

We present an experimental study of the generation of internal waves by the horizontal oscillations of a disk in a stratified fluid. Viscosity is the motor of the generation mechanism through the no-slip condition at the surface of the disk. Velocity fields are measured by particle image velocimetry and show that the waves form steady cross-shaped wave beams. Comparison with the theory of Davis & Llewellyn Smith (J. Fluid. Mech. 2010) exhibits good prediction of the wave profile but also a surprising underestimation of the wave amplitude at small amplitude of oscillation.

Domaines: Mécanique des fluides [physics.class-ph]; Mécanique des fluides [physics.class-ph]

Sylvain Joubaud, Bruno Voisin, Thierry Dauxois. Tangential oscillations of a disk in a stratified fluid. Geophysical and Astrophysical Internal Waves Conference, Feb 2011, Les Houches, France. ⟨hal-00583424⟩