Experimental investigations and aerodynamic shape optimization of small horizontal-axis wind turbine blades

Abstract

This study aims to optimize and investigate small horizontal-axis wind turbine blades at low wind speeds. The objective of this study is to explain the design method based on BEM theory for 0.2 m blade rotors with constant, variable, and linear chord with twisted blade geometry. MATLAB and Xfoil programs were used to apply BEM principles on wind turbines with SG6043 airfoil. Numerical and experimental studies were carried out to examine the impact of rotor solidity values from 0.057 to 0.207 and the number of blades from 3 to 7. The experimental blades were developed using a 3D printing additive manufacturing technique. The rotors were investigated in an open wind tunnel at wind speeds ranging from 2 to 8 m/s. The initial investigation range included tip speed ratios from 2 to 8 and angles of attacks from 2° to 20°. Subsequently, these parameters were varied in Matlab and Xfoil software to optimization and investigate the power coefficient, blade geometry, number of blades, and blade pitch angle. It was found that a rotor solidity of 0.055–0.085 displayed better performance.