A New Approach to the Improvement of k-ε Turbulence Model for Wall-Bounded Shear Flows

Abstract

An improved near-wall k-ε turbulence model is proposed considering the two characteristic length scales for the dissipation rate, one very near the wall and the other remote from the wall, which are then related to the length scale for turbulent momentum transfer. Consequently, the function fμ included in the eddy diffusivity model represents two distinct physical effects of low turbulent Reynolds number and wall proximity. The present k-ε model is evaluated for its application to fully developed turbulent pipe and channel flows and found to resolve two serious weaknesses common to previous k-ε models; i.e., it correctly predicts the wall-limiting behavior of the major turbulence quantities such as Reynolds stress, turbulent kinetic energy and its dissipation rate near the wall, and the distributions of eddy diffusivity of momentum and turbulent kinetic energy even in the region far from the wall.