Analysis of the impact of separate bionic wake deflectors on the performance of vertical-axis wind turbines

Inspired by the tail morphology of oceanic flying fish, this study proposes a novel bionic deflector integrated at the trailing edge of vertical-axis wind turbine blades to mitigate aerodynamic performance limitations induced by dynamic stall. Through comprehensive two-dimensional and three-dimensional computational fluid dynamics simulations combined with orthogonal design of experiments, we systematically investigate the influence of key parameters on bionic flow guidance across tip speed ratios ranging from 1.44 to 3.30. The results demonstrate a 13% enhancement in the power coefficient with the wake deflector implementation. Comparative blade surface analysis reveals that the deflector substantially improves the mean torque generation of individual blades, directly contributing to overall turbine performance. Pressure distribution analysis further indicates that the deflector's modification of the original blade's pressure coefficient distribution constitutes a primary mechanism for performance enhancement. Flow field visualization confirms that the deflector effectively suppresses suction-side vortex separation and delays flow detachment, leading to significant improvements in turbine aerodynamic efficiency.