Turbulent Wake in a Stratified Medium (Trubulentnyy Sled v Stratifitsirovannoy Srede).

摘要

The article discusses the problem of determining the shape of a turbulent wake formed behind a self-propelled body in a medium with a density variable in the direction of action of gravity. A schematic picture of the development of the wake behind the moving object is as follows: at the outset, the diffusion is the same in all directions, and the wake expands symmetrically; with increasing distance from the object, the diffusion becomes strongly anisotropic, it decreases in the vertical direction under the action of gravity, and the wake assumes a flattened shape; in the volume occupied by the wake, turbulent mixing within the wake gives rise to a more homogeneous density distribution than in the ambient medium; this volume of liquid is no longer in a state of equilibrium and, acted upon by gravity, tends to return to this state; the wake collapses, and this is accompanied by its further expansion in the horizontal direction and excitation of internal waves.