Drag reduction of wake flow by shear-driven rotation

This paper proposes a control strategy in which immersed bodies are driven to rotate not by external forces but by the flow itself. Due to the asymmetric distribution of the shear stress exerted on the surfaces, two side-by-side arranged cylinders rotate about their axes to produce moving fluid-solid boundaries. It is shown that the drag and the lift coefficients are significantly reduced in comparison with the stationary cylinder system. Different from the slip-boundary technique, the drag-reduction mechanism is explained in terms of a pressure-recovery effect introduced by the rotating surfaces. DOI: 10.1103/PhysRevE.87.023013