An introduction to the modelling of turbulence
Abstract
Turbulent flow models are reviewed. A turbulent flow can be obtained under the following conditions: at moderate Reynolds numbers the restraining effects of viscosity are too weak to prevent small, random disturbances in a shear flow from amplifying; the disturbances grow, become nonlinear and interact with neighboring disturbances; this mutual interaction leads to a tangling of vorticity filaments; the flow reaches a chaotic, nonrepeating form describable only in statistical terms. Direct numerical simulations of turbulent shear flows, based on time dependent NavierStokes equations, are discussed. Mathematical and physical statements on forming turbulent transport equations are summarized. Velocity distribution and heat and mass transports in turbulent flows are overviewed.
 Publication:

VKI An Introduction to Modeling Turbulence
 Pub Date:
 1993
 Bibcode:
 1993VIMT.....Q....L
 Keywords:

 NavierStokes Equation;
 Turbulence Models;
 Turbulent Flow;
 Flow Velocity;
 Heat Transfer;
 Mass Flow Rate;
 Reynolds Number;
 Shear Flow;
 Velocity Distribution;
 Viscosity;
 Fluid Mechanics and Heat Transfer