Aerodynamic optimization of a Darrieus-Savonius wind turbine with guide vane for power generation in the coastal area of Pacitan Regency

Pacitan Regency has a coastline of 116.2 km with wind speeds ranging from 2 to 10 m/s, making it a potential site for small-scale wind power generation. However, the utilization of wind energy at low wind speeds still faces efficiency challenges, necessitating the development of more optimal turbine designs. This study aims to optimize the aerodynamic performance of a Darrieus–Savonius wind turbine through the addition of guide vanes to improve efficiency under low wind speed conditions. This research employs a numerical simulation method based on Computational Fluid Dynamics (CFD) using OpenFOAM software. The parameters analyzed include the power coefficient (Cp), torque coefficient (Ct), and the flow characteristics around the turbine. Simulations were conducted at a wind speed of 10 m/s using the k-ω SST turbulence model. The results indicate that the number of guide vanes significantly affects the performance of the combined Darrieus–Savonius wind turbine. The addition of guide vanes helps to direct the airflow toward the rotor, thereby increasing torque. However, excessive numbers of guide vanes lead to increased turbulence and torque fluctuations, resulting in negative drag moments. Based on the comparison of several configurations, the use of four guide vanes provides the optimal performance, yielding the highest torque and power compared to configurations with three and five guide vanes.