Numerical study of the aerodynamic and acoustic benefits of novel arc-shaped trailing-edge serrations for vertical axis wind turbine

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Trailing-edge serrations effectively mitigate aerodynamic noise and improve the performance of static airfoils, yet their application to vertical axis wind turbine (VAWT) remains insufficiently explored. This study proposes novel arc-shaped trailing-edge serrations for VAWT blades, parametrically designed using Bézier curves. Using Large Eddy Simulation (LES) coupled with the Ffowcs Williams–Hawkings (FW-H) acoustic analogy, three curved configurations (BS-0.25, BS-0.5, BS-0.75) are systematically compared with a base case and conventional triangular trailing-edge serrations (TES) at tip speed ratios (TSRs) of 1.47, 1.78, and 2.24. The serrations mitigate dynamic-stall hysteresis, alter coherent vortical structures, and suppress load fluctuations. BS-0.5 yields the greatest aerodynamic improvement, raising the power coefficient by about 20% while reducing torque fluctuations. Acoustically, all serrated cases suppress low-to-mid-frequency noise, with BS-0.75 most pronounced, achieving sound pressure level (SPL) reductions of up to 3–4 dB. These results reveal a trade-off between aerodynamic efficiency and acoustic performance: BS-0.5 is recommended for power-centric designs, whereas BS-0.75 is optimal for noise-sensitive environments. This work provides practical guidance for optimizing blade designs to balance aerodynamic efficiency and noise mitigation under diverse engineering requirements.