3D numerical analysis of an H-rotor darrieus vertical axis wind turbine in transient regime

This study presents a comprehensive 3D numerical analysis of a Vertical Axis Darrieus H turbine, focusing on performance in transient regimes. The analysis aims to establish the optimal design parameters to enhance the turbine’s energy extraction from airflow , considering transitions between attached flow and dynamic stall. Utilizing CFD , the aerodynamic profiles of three blade designs (NACA 0015, NACA 0021, S-1046) under different pitch angles ( β = 0 ∘ , − 2 ∘ , and − 6 ∘ ) are investigated. The findings indicate that the pitch angle significantly influences the turbine’s Power Coefficient and performance. Specifically, while β = 0 ∘ yields the highest peak power coefficient in specific profiles, β = − 2 ∘ generally enhances steady-state performance for the NACA 0015 and NACA 0021 profiles. The dynamic nature of torque and power generation reveals the importance of modeling turbine behavior in free rotation to capture performance characteristics accurately. The results underscore the need for further exploration into varying pitch angles and blade designs. This work contributes to understanding vertical axis wind turbine performance in transient regimes and provides a foundation for future research. • 3D CFD analysis enhances understanding of VAW performance in transient regimes. • Optimal blade design and pitch angles significantly improve turbine power efficiency. • NACA0021 profile with − 2 ∘ pitch angle outperforms in steady-state conditions. • Free rotation modeling reveals dynamic stall’s impact on turbine power generation.