Airfoil types effect on geometry and performance of a small-scale wind turbine blade design

Abstract

Many airfoils could be used to form a wind turbine blade. Different airfoil would result in an altered blade planform and its performance characteristics. Airfoil identifi cation that should be included in the design then becomes an important task. Utilizing Blade Element Momentum Theory computation procedures, eleven types of airfoils were applied in blade geometries of rotors of 2.4 m in diameters. The changes in the distribution of chord lengths, twists, solidity ratio, and Reynolds numbers of the blades were compared as geometry parameters. The designed and off designed powers and thrusts were calculated, and the characteristics of the performance of the rotor were represented by the coeffi cient of power and coeffi cient of thrust.The calculated geometries showed that distinct airfoils resulted in different segments sizes of the blades and different performance characteristics of the rotors. The use of an airfoil that has a high lift coeffi cient and a high glide ratio in the design of a blade will produce a narrow blade and a small solidity ratio. The design will also have a high power coeffi cient at the tip speed ratio design. However, the blade power coeffi cient may be sensitive to changes in rotational speed.