Localized disturbances and their relation to turbulent shear flows

Abstract

The resemblance among coherent structures naturally occurring in fully developed bounded turbulent shear flows, transitional flows and free shear layers suggests the existence of a basic single mechanism responsible for the formation of the structures under various base flow conditions. The common elements in all such flows are the shear of the base flow and the presence of a localized vortical disturbance within this shear. The objective of the present study is to examine the capability of a simple model of interaction between a localized vortical disturbance and the surrounding 'simple' laminar shear flow where the velocity vector is (at most) a linear function of the coordinates, to repro..