Performance of a Novel, Flapping Vertical Axis Wind Turbine of the Savonius Derivative

Abstract Savonius turbines have attracted attention due to their simple construction and versatility in wind energy conversion. In contrast to their horizontal axis counters, these turbines can harness wind energy from any direction, making them suitable for low-speed wind conditions, including urban environments. Furthermore, Savonius is less noisy when compared to horizontal axis wind turbines. However, due to the opposing aerodynamic forces acting on the retreating blade, the rotor exhibits relatively low efficiency. The range of the coefficient of power for the Savonius turbine is between 0.1 and 0.25. Many configurations have been proposed to enhance the rotor efficiency, which include enhancing key design features such as the aspect ratio, tip speed ratio, and the shape of the blades. End plates, guide vanes, deflecting plates, etc. have been used to boost the performance of Savonius turbines. In this work, we propose a flexible blade, a promising approach, that reduces the drag on the retreating blade while increasing the lift on the forwarding blade. This study examines the aerodynamic behavior and performance of flexible blades using a combined approach of experimental analysis and numerical simulations performed in ansys fluent. The results from both experimental tests and computational fluid dynamics simulations show that the power coefficient of the proposed flexible blade was about 17% higher than that of the rigid blade for most of the wind speed regime.