Development of a k–ω–ϕ–α turbulence model based on elliptic blending and applications for near-wall and separated flows

摘要

A new turbulence model based on elliptic blending, termed as k − ω − ϕ − α model, is developed. This model uses the latest version of Wilcox's k − ω model in near-wall region and changes gradually to the BL−v2/K model elsewhere. The capabilities of the present model are evaluated on near-wall and separation flows, i.e. the 2D fully developed channel flow, the asymmetric plane diffuser flow and the 2D backward-facing step flow, in comparison with available direct numerical simulation (DNS) and experimental data. The computational results are compared also to those from the popular BL−v2/K model and the original BL−v2/K model, and the present model is more stable than the BL−v2/K model in complex flows. The present model provides indistinguishable velocity profiles and improved turbulent kinetic energy profiles compared to the BL−v2/K model in the channel flow, while in the separation flows tested herein, the present model can obtain comparable results with the BL−v2/K model, and both of them show improvements to some extent compared with the BL−v2/K model.