Design of glass fiber reinforced composite blades for a 1 kW small-scale wind turbine

Abstract

This study presents the design and fabrication of small-scale wind turbine (SWT) blades using Glass Fiber Reinforced Polymer (GFRP), considering aerodynamic and structural aspects in order to meet the growing energy demand in Sri Lanka through renewable energy solutions. The turbine blade is designed to generate 1 kW of power with a rotor diameter of 2.2 meters and consists of a combination of NACA 4412 and SG6043 airfoils and achieves a remarkable power coefficient (Cp) of 0.448 at a tip speed ratio (TSR) of 6. The chord length and twist angle variation from the root to the tip has been set to optimize aerodynamic performance at different wind conditions. The aerodynamic analysis was performed using blade element momentum theory, and the structural analysis employed the boom-shell method to determine internal stresses accurately. Results verified stresses within acceptable limits, ensuring structural integrity near cutoff wind speeds. Additionally, material testing was conducted to verify the reliability of the composite design used. Subsequently a dynamic analysis was conducted to ensure stable performance with minimal flapping under varying conditions. Therefore, this project offers a cost-effective, efficient, and locally manufactured solution to contribute to Sri Lanka's renewable energy goals by supporting small-scale wind power generation.