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

A new turbulence model based on elliptic blending, termed as k - omega - phi - alpha model, is developed. This model uses the latest version of Wilcox's k - omega model in near-wall region and changes gradually to the BL - upsilon(2)/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 flowand the 2Dbackward-facing step flow, in comparisonwith available direct numerical simulation (DNS) and experimental data. The computational results are compared also to those fromthe popular SST k - omega model and the original BL - upsilon(2)/k model, and the present model is more stable than the BL - upsilon(2)/k model in complex flows. The present model provides indistinguishable velocity profiles and improved turbulent kinetic energy profiles compared to the BL - upsilon(2)/k model in the channel flow, while in the separation flows tested herein, the present model can obtain comparable results with the BL - upsilon(2)/k model, and both of them show improvements to some extent compared with the SST k - omega model.