Three-zonal Wall Function for k-ε Turbulence Models

Most commercially available wall functions for k-" turbulence models base on the two-zonal near-wall flow division assumption. Viscous and log-law sublayers are distinguished. In this article the three-zonal wall function concept with a buffer sublayer is developed. The aim of this new wall function is to improve the mean streamwise U+ velocity profile. The proposed wall function is validated on backward-facing step experimental data. Physical implications of the model performance are also discussed.