Advanced Blade Profiles for Improved Efficiency in Savonius Wind Turbines: The Aeroleaf Case Study

Abstract The Aeroleaf wind turbine, a modified Savonius vertical-axis wind turbine (VAWT), offers promising potential for urban environments but suffers from limited aerodynamic efficiency. This study investigates the impact of different pre-optimized blade profiles—elliptical, Roy, S-shaped, and scooplet—on the performance of the Aeroleaf turbine using unsteady numerical simulations with the k-ε Realizable turbulence model. Among the studied designs, the scooplet-based turbine demonstrated the highest performance, achieving a peak Power Coefficient (Cp) of 0.18 at a Tip-Speed Ratio (TSR) of 0.6, marking a 68.2% improvement over the original Aeroleaf. Additionally, it exhibited the highest static torque (0.443 N·m), ensuring superior self-starting capability. The S-shaped profile also showed a significant enhancement, reaching a peak Cp of 0.156 at TSR = 0.7, but with slightly lower static torque. The Roy-profile turbine attained a C_p of 0.132 at TSR = 0.7 (23.4% improvement), while the elliptical-profile design exhibited the least improvement, with a peak Cp of 0.124 at TSR = 0.6 (15.9% increase). The findings highlight the potential of utilizing optimized blade profiles to enhance the aerodynamic efficiency and self-starting capability of VAWTs. The scooplet-based turbine emerged as the most effective design, making it a promising candidate for small-scale wind energy applications.