Effects of near-wall turbulence model on numerical simulation of turbulent separated flows

Turbulent separated flows appear in the near wall flow region. The near wall turbulence models play an important role in predicting turbulent separated flows. In this paper we investigate the effects of three near wall turbulence models on numerical simulation of turbulent separated flows. These three turbulence models are two layer turbulence model, low Reynolds number turbulence model and wall function model. In order to criticize the behavior of the turbulence models, we computed the two turbulent separated flows around a hill and many hills distributed periodically with these turbulence models, and then compared the numerical solutions with measured data. The results show that the two layer turbulence model and low Reynolds number turbulence model have the similar behavior to predict turbulent separated flows. Basically they can give the reasonable solutions. But the wall function model leads to wrong flow structures because of the assumption of the log law.