REVIEW OF EXPERIMENTAL AND NUMERICAL STUDIES ON THE PERFORMANCE OF SAVONIUS WIND TURBINES

Abstract

Due to its simplicity, omnidirectionality, and low-wind start, the Savonius vertical-axis wind turbine (VAWT) may be suitable for small-scale renewable energy production. Its low power coefficient (Cp) compared to lift turbines hinders its large-scale use. This review examined recent experimental and numerical studies to solve this constraint. Key geometric elements include aspect ratio, blade number, overlap ratio, arc angle, blade profile, and operating techniques contribute to performance. The current study reviews recent improvements including improved aerodynamic modifications, crescent-like and omnidirectional deflectors (which increase Cp by up to 125%), curtain-fins, and new blade designs like the SR5050 profile, making it unique. The review also synthesises discoveries in advanced configurations including multi-stage rotors and hybrid Darrieus-Savonius systems, which combine the best of both worlds. Validating performance improvements and design optimization requires CFD. Results show that deliberate design adjustments can increase Cp values to 0.38, a significant improvement. We have achieved this, but future studies must include scalability, cost-effective production of intricate geometries, and field trials to decrease the efficiency gap and realize Savonius VAWTs' renewable energy potential.