The effects of curvature in wall-bounded turbulent flows

Abstract

Low-Reynolds-number, mildly curved, turbulent channel flow has been simulated by direct numerical solution of the Navier – Stokes equations. Computed velocity fields were found to be in good agreement with experimental measurements. The resulting flow fields were used to study the effects of streamline curvature by comparing the concave and convex sides of the channel. Observed effects are consistent with experimental measurements for mild curvature. The most significant difference in the turbulence statistics is in the Reynolds shear stress. This is accompanied by significant differences in the terms of the equation for Reynolds-shear-stress budget. In addition, it was found that stationary Taylor – Görtler vortices were present and that they had a significant effect on the flow by contributing to the mean Reynolds shear stress, enhancing the asymmetry of the channel, and affecting the underlying turbulence.