Post-NACA Aerodynamics: Optimizing H-Darrieus VAWT Design with CFD Simulations of Novel J-Blades

Abstract As the demand for sustainable energy sources continues to rise, improving the efficiency of existing renewable technologies is crucial. This study investigates the aerodynamic performance of a novel J-shaped blade design for H-Darrieus VAWT with the objective of enhancing starting torque and overall efficiency. A 2D URANS CFD model was employed to simulate the airflow around the J-shaped blades. The model underwent a comprehensive verification and validation process. This rigorous approach ensured the model's fidelity, enabling a systematic comparison of the J-shaped blade's aerodynamic performance with conventional NACA0015 airfoils. The numerical analysis reveals a significant enhancement in starting torque, with a 142% increase observed at low tip speed ratios (λ = 0.2). This finding positions the J-shaped blade as a promising solution to address the challenge of initiating rotation in low-wind environments, particularly relevant for urban applications. Furthermore, the simulations demonstrate comparable torque production between the J-shaped blade and the NACA0015 airfoil under typical operating conditions. The J-shaped blade exhibits improved torque uniformity and reduced wake turbulence intensity. This study highlights the potential of the J-shaped blade design to revolutionize VAWT technology by offering advancements in increased efficiency, reduced fatigue stresses on the turbine structure, and optimized energy generation.