Modeling of nearwall turbulence
Abstract
An improved kepsilon model and a second order closure model is presented for low Reynolds number turbulence near a wall. For the kepsilon model, a modified form of the eddy viscosity having correct asymptotic near wall behavior is suggested, and a model for the pressure diffusion term in the turbulent kinetic energy equation is proposed. For the second order closure model, the existing models are modified for the Reynolds stress equations to have proper near wall behavior. A dissipation rate equation for the turbulent kinetic energy is also reformulated. The proposed models satisfy realizability and will not produce unphysical behavior. Fully developed channel flows are used for model testing. The calculations are compared with direct numerical simulations. It is shown that the present models, both the kepsilon model and the second order closure model, perform well in predicting the behavior of the near wall turbulence. Significant improvements over previous models are obtained.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 1990
 Bibcode:
 1990STIN...9028009S
 Keywords:

 Closure Law;
 Eddy Viscosity;
 KEpsilon Turbulence Model;
 Turbulent Flow;
 Wall Flow;
 Asymptotic Methods;
 Channel Flow;
 Computerized Simulation;
 Kinetic Energy;
 Low Reynolds Number;
 Pressure Distribution;
 Reynolds Stress;
 Fluid Mechanics and Heat Transfer