Turbulent flow acceleration and abnormal intensification of the separated flow in a channel with dense arrangement of inclined single-row oval-trench dimples

Abstract

On the basis of the Reynolds-averaged Navier-Stokes equations closed by the shear stress transport model with the consideration of streamline curvature, turbulent flow acceleration in the channel with inclined single-row oval-trench dimples, earlier found in the laminar regime, has been revealed. It is shown that the velocity in the flow core increases up to 1.4 times when dimples are densely packed. The influence of the dense arrangement of dimples on abnormal intensification of the separated flow in the stabilized area of the channel has been assessed. Absolute friction in the backflow zone in the dimple is found to grow up to 5.5 times compared with friction at the smooth channel wall.