Rotor solidity and blade pitch influence on horizontal axis small wind turbine performance – Experimental study

Abstract

The urgent need to reduce greenhouse gas emissions has accelerated the adoption of renewable energy sources such as wind power. In this context, small wind turbines (SWTs) have emerged as a viable solution for decentralized electricity generation. This paper investigates the combined influence of rotor solidity and pitch angle variation on the performance of a small horizontal axis wind turbine through experimental analysis conducted in a wind tunnel. Results show that increasing rotor solidity generally improves Cpmax, particularly for shorter chord blades, with up to a 25–35 % increase observed by increasing the number of blades and a 10–15 % increase by employing longer chord blades compared to benchmark designs. Additionally, the study highlights the significant sensitivity of turbine performance to slight changes in pitch angle resulting in a 4–8 % rise in Cpmax. Higher solidity rotors exhibit reduced sensitivity to pitch angle changes and reference velocity variations, contributing to improved stability in varying environmental conditions. The study highlights the influence of aerofoil Reynolds number on turbine performance, underscoring the importance of careful aerodynamic design considerations. It provides valuable insights for SWT design to enhance energy efficiency and promote the widespread adoption of wind energy technology.