Tangential oscillations of a disk in a stratified fluid

International audienceWe 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