An exploration to the modelling of twodimensional complex turbulent shear flows
Abstract
Regions with shearstress and meanvelocity gradients of opposite sign often exist in complex turbulent shear flows. In these cases, the eddyviscosity hypothesis breaks down. Hinze (1970) attributed this to transportation of mean momentum over distance by the large structures and arrived at a shearstress expression including the secondorder derivatives of the mean velocity. However, he gave correct results only qualitatively. Here, the same expression is investigated further and found to overestimate the shear stress greatly. This means that the flow particles are unlikely to have enough memory of the mean momentum over distance. By assuming that the departure from the eddyviscosity hypothesis is a result of transportation of shear stress contained in smaller eddies over distance by the large structures, a new shearstress expression is obtained. The shearstress estimates so far were in good agreement with experiments.
 Publication:

Acta Aeronautica et Astronautica Sinica
 Pub Date:
 January 1987
 Bibcode:
 1987AcAAS...8...20Z
 Keywords:

 Computational Fluid Dynamics;
 Flow Deflection;
 Shear Flow;
 Turbulent Flow;
 Two Dimensional Flow;
 Eddy Viscosity;
 Velocity Distribution;
 Fluid Mechanics and Heat Transfer