Wakes of Maneuvering Body in Stratified Fluids

Summary

When submerged self-propelled body makes a maneuver, it imparts net momentum on the surrounding fluid. Using experimental observations and theoretical arguments we show that in a stratified fluid this leads to impulsive momentum wakes with large, long-lived coherent vortices in the late flows, which may be used as a signature for identification of submarine wakes in oceanic thermocline. We also show that in a strongly stratified fluid the drag on the body due to radiating internal waves may be significant and cause the wake to receive an extra momentum.