CFD-Based Aerodynamic Modelling and Performance Optimization of an H-Darrieus Vertical-Axis Wind Turbine

Vertical-axis wind turbines (VAWTs) have become an effective solution for electricity generation in local grids, especially in the low wind speed and turbulence conditions often found in urban areas. Despite the progress made, the aerodynamic performance of these turbines is still limited due to the complex nature of the airflow and some fundamental design issues. This study aims to improve the aerodynamic efficiency of vertical axis wind turbines by investigating the influence of key design parameters on their performance using computational fluid dynamics (CFD) calculations. The main scientific value of this work is to determine the optimal ratio of the tip speed (TSR) and blade pitch angle that provides maximum aerodynamic efficiency of the turbine, thus improving the energy conversion capabilities compared to the results of previous studies. In ANSYS Fluent, the k turbulent model was used to accurately describe the unstable flow around the blade and determine the pressure and velocity fields. The results indicated that the wind turbine attained maximum aerodynamic performance at a blade pitch angle of 1.5 radians and a tip speed ratio (TSP) of 4.9, reaching an optimal power factor (Cp) of 0.52, showing a notable improvement in overall power conversion efficiency of the system. This research proves that advanced CFD calculations help design better low- and medium-wind VAWTs, enhancing their role in sustainable energy.