A Study of a Model for the Generation of Internal Waves by a Moving Body and Its Turbulent Wake

We test a previously proposed model for the generation of internal waves, produced both by the flow over the body and the disturbances produced by its turbulent wake, within the framework of a ray model of the internal waves. This model approximates the stratified flow over the sphere as a combination of a distribution of sources representing the steady internal wave flow, relative to the sphere, and a vertically oscillating sphere, representing the waves generated by the turbulent eddies in the wake. The results of our ray simulations are compared with the few existing laboratory experiments of a towed sphere that oscillates at a fixed frequency in the vertical in a uniformly stratified tank and with some new numerical simulations. We find that the ray calculations using the model source term compare well with the numerical simulations of the laboratory experiments, and these results lead to some insights into how the model can be improved to simulate a fully turbulent wake.