Toward silent wind energy: Aerodynamic noise reduction research for large wind turbine blades based on fish scale-inspired bionic structures

In order to reduce aerodynamic noise from large wind turbines, this study proposes a fish scale-inspired tip structure. Based on the geometrical characteristics of fish scales, Large Eddy Simulation (LES) and FW-H acoustic analogy methodologies were applied to methodically examine the noise suppression mechanisms across two design configurations. Comparative analysis of the acoustic characteristics, vortex structures, and spectral patterns with those of the prototype wind turbine reveals that the biomimetic fish scale structure markedly diminishes noise source intensity by cutting off tip vortices and accelerating vortex dissipation. Among these, the S-rs1 scheme achieves a minimum sound pressure level of 81.13 dB (at the 240° direction), representing a maximum noise reduction of 8.5 dB compared to the prototype blade, and a reduction of 4.0 dB in fundamental frequency noise at the critical monitoring point (57, 2, 0) in the near-wake region; The P-rs5 scheme reduced noise by 7.9 % in the radial range of 60–140 m, with the noise reduction effect increasing with distance. This study confirmed the possibility for synergistic enhancement of aerodynamic and acoustic performance, offering a biomimetic strategy for the low-noise design of large wind turbine apparatus.