Passive flow control mechanisms with bioinspired flexible blades in cross-flow tidal turbines

Abstract State-of-the-art technologies for wind and tidal energy exploitation focus mostly on axial turbines. However, cross-flow hydrokinetic turbines possess interesting features, such as higher area-based power density in array installations shallow water, well a generally simpler design. Up to now, the highly unsteady flow conditions cyclic blade stall have hindered deployment at large scales because of resulting low single-turbine efficiency fatigue failure challenges. Concepts exist which overcome these drawbacks by actively controlling flow, cost increased mechatronical complexity. Here, we propose bioinspired approach with hyperflexible turbine blades. The rotor naturally adapts through deformation, reducing separation passive manner. This results lifetime decreased structural loads, without compromising simplicity Graphic abstract