Evolution of Localized Vortex Disturbance in Uniform Shear Flow: Numerical Investigation

Abstract

The possibility that a simple model of interaction between a localized vortical disturbance and laminar uniform unbounded shear flow is capable of reproducing the generation mechanism and characteristics of coherent structures naturally occurring in wall bounded turbulent flows is examined numerically. Gaussian and toroidal vortices are used as the initial disturbances. The concentrated vorticity field of the Gaussian vortex is defined by a single length scale 6, which is assumed to be much smaller than the characteristic scale of the base flow. The toroidal disturbance is defined by two length scales r 0 and δ, corresponding to the radius and thickness of the torus, respectively