Fine Structure of a Stratified Flow around a Fixed and Slow-Moving Wedge

Resumo

The dynamics of the establishment and spatial structure of flows of a continuously stratified fluid around a fixed and slow-moving horizontal wedge are studied using direct numerical simulation based on the fundamental system of inhomogeneous fluid mechanics equations. Large-scale components (eddies, internal waves, and the wake) and fine-structure components are isolated in the flow patterns in near and away from the obstacle. The mechanism of formation of the propulsive force generating the self-motion of a free body at a neutral-buoyancy horizon is determined. The dependence of the flow parameters on the shape of the obstacle is shown. The transformation of the medium perturbation field at the beginning of the induced slow movement of the wedge at the neutral-buoyancy horizon is traced. The complex structures of fields of different physical quantities and their gradients are visualized. The intrinsic temporal and spatial scales of the flow components are identified.