Internal wave generation by oscillation of a sphere, with application to internal tides

摘要: A joint theoretical and experimental study is performed on the generation of internal gravity waves by an oscillating sphere, as a paradigm tides barotropic tidal flow over three-dimensional supercritical topography. The theory linear three-dimensional, applies both near far from takes into account viscosity unsteadiness arising interference with transients generated at start-up. propagate in conical beams, evolving distance bimodal to unimodal wave profile. In field, profile asymmetric its major peak towards axis cones. experiments involve horizontal oscillations develop cross-correlation technique for measurement deformation fluorescent dye planes sub-pixel accuracy. At oscillation amplitude one fifth radius are agreement between experiment excellent. As increases half radius, nonlinear effects cause saturate value that 20% lower than estimate. Application conversion rate energy confirms expected scaling flat topography, shows transformation hemispherical ocean, viscous unsteady have essentially local role, keeping finite edges otherwise dissipate such large distances they hardly induce any decay.