An improved <f>k−ω</f> turbulence model applied to recirculating flows

In this paper an improved <f>k−ω</f> turbulence model is proposed, which brings the asymptotic boundary value for <f>ω</f> into accord with direct numerical simulation (DNS) data. In the new <f>ω</f>-equation both a turbulent and a viscous cross-diffusion term are included, justified by an analogy to the Yap-correction and the pressure-diffusion process, respectively. The importance of cross-diffusion terms in removing the freestream sensitivity with respect to <f>ω</f> for free shear flows is shown. The performance of the model is evaluated and compared with DNS and with other turbulence models in a channel flow, a backward-facing step flow and a rib-roughened channel flow with heat transfer. The model requires neither wall-function nor wall-distance information and is fully integrable over the near-wall region. [Copyright &y& Elsevier]