Subsurface Signature of the Internal Wave Field Radiated by Submerged High Reynolds Number Stratified Wakes

摘要

The work funded by this grant has examined the internal wave field emitted by a stratified turbulent wake of a towed sphere over a range of body- based Reynolds and Froude numbers using implicit Large Eddy Simulation. The subsurface signature of these waves in an idealized linear stratification has also been studied. Preliminary investigations have also been made to decompose wake turbulence and internal waves using Proper Orthogonal Decomposition. In parallel with the high-computational-cost full wake studies, we have examined the complex nonlinear physics of a more idealized problem, that of a two- dimensional internal wave beam and its interactions with a varying background density profile (namely a localized model pycnocline) and its reflection with a free-slip surface. In this regard, research has focused on Eulerian and Lagrangian mean flow formation, harmonic generation and parametric subharmonic instability.