Investigation of the blade tip geometry for improved performance of a Savonius rotor
Ahmed Ayadi, Nour Rabeh, Jihen Marzougui, Ridha Ennetta, Zied Driss
Abstract
• A numerical investigation was conducted on a Savonius wind rotor. • Novel configurations modify blade ends, rotor center, or both, improving power output. • Optimized shape improves power coefficient by 20.76 % at TSR 1.2. • Several proposed cases showed better power coefficients than the standard rotor. Savonius wind rotors are highly effective at capturing wind energy due to their unique design, which includes vertically curved blades that can harness wind from multiple directions. This study focuses on optimizing the performance of a two-bladed Savonius wind rotor using Computational Fluid Dynamics (CFD) simulations in ANSYS Fluent, with results validated against experimental data. Novel blade shapes are assessed to determine their impact on torque generation, power output, and key performance indicators such as velocity and pressure distributions. Three configurations are proposed, including modifications at the blade ends, modifications near the rotor center, and combined modifications at both the ends and the center. The results demonstrate that optimizing blade geometry can significantly enhance torque generation and power output, leading to improved energy capture. Specifically, several modified Savonius rotors have achieved higher power coefficients (Cp) compared to the standard Savonius rotor design. Among these cases, the optimized configuration reached a peak power coefficient of 0.285 at a Tip Speed Ratio (TSR) of 1.2. This represents a 20.76 % improvement over the standard Savonius rotor at the same TSR.