An Algebraic Stress Model for Near-Wall Regions.

Abstract

The algebraic stress model for high Reynolds number is extended to the near-wall region of low Reynolds number. In developing the model, convection and diffusion terms are approximated to take viscous effect into consideration by applying Rodi's proposal. The pressure strain term and dissipation term of the Reynolds stress equation are modified by introducing the invariant function. The transport equations for turbulent energy and the dissipation are standard two-equation models adopted for the near-wall region. To examine the proposed model, numerical analysis has been performed on a fully developed turbulent flow in a square duct. Calculated results are compared with the experimental data available and the calculated results obtained by using an algebraic stress model for high Reynolds number. The proposed model can predict more precisely wall shear stress and normal stress in the mean flow direction than can the model for high Reynolds number, but the results of normal stress in the secondary flow direction are slightly different from the experimental data.