CFD Investigation on Aerodynamic Performance of Variable Pitch Blades Under Low Wind Speed Conditions

Renewable energy refers to energy sources that are naturally replenished and can be sustained over time. These include solar, wind, hydro, geothermal and biomass energy. Among these, wind energy has emerged as a key contributor to global energy demands due to its efficiency and decreasing cost. In the early stages of wind energy development, most wind turbines operated at a constant speed. However, there has been a recent increase in the installation of variable pitch-blade wind turbines in wind farms, with more manufacturers producing this type of turbine. The use of variable pitch blades offers significant advantages, particularly in regions with low wind speeds. Studying the aerodynamic performance of blades at various pitch angles is essential in initiating the design process of horizontal-axis wind turbines (HAWTs) to achieve optimal performance. This investigation focuses on the performance of variable pitch blades between 0° which is rigid blade until 25°, particularly under low wind speed conditions found in Malaysia. The purpose of this research is to study the aerodynamic behaviour of HAWT blades and determine the most efficient blade chord design. Computational Fluid Dynamics (CFD) simulations using ANSYS Fluent are employed to evaluate blade performance across different pitch angles and wind speeds. The results reveal that varying the pitch angle significantly affects the flow behaviour and aerodynamic characteristics of the blades. Specific pitch angles show improved lift generation and reduced flow separation, which contribute to higher turbine efficiency under low wind speed conditions. In conclusion, the use of variable pitch blades in HAWTs can enhance aerodynamic performance and energy output in low-wind regions. The findings of this study provide valuable insights into blade design optimization, supporting the development of more efficient wind turbine systems.