Numerical analysis of twodimensional unsteady turbulent shear flow by discrete vortex model
Abstract
For the calculation of twodimensional turbulent shear flows by the discrete vortex model, a numerical scheme by which motions of a system composed of many vortices can be calculated accurately is proposed. It is verified that the rollingup process of the vortex sheet presented by Rosenhead (1931) is calculated accurately by this scheme. The present method is applied to the study of an unsteady turbulent shear flow which is represented by two hundred vortices with random vortex strengths and with initial random locations given by random numbers. As a result it is found that a coherent structure with a spiral form is realized in the turbulent flow, and the thickness of the turbulent shear layer increases linearly with time. It is shown that the calculated mean velocity, longitudinal and transversal turbulent intensities, and the Reynolds stress develop with time in the selfsimilar manner governed by the length scale of the turbulent shear layer thickness.
 Publication:

JSME International Journal Series B
 Pub Date:
 January 1985
 Bibcode:
 1985JSMEB..28...62T
 Keywords:

 Computational Fluid Dynamics;
 Numerical Flow Visualization;
 Shear Flow;
 Turbulence Models;
 Turbulent Flow;
 Two Dimensional Flow;
 Vortices;
 Flow Velocity;
 Reynolds Stress;
 Shear Layers;
 Thickness;
 Unsteady Flow;
 Fluid Mechanics and Heat Transfer