Geometrical Design of a Rotor Blade for a Small Scale Horizontal Axis Wind Turbine

Abstract

In the present study, Blade Element Momentum theory (BEMT) has been implemented to heuristically design a rotor blade for a 2kW Fixed Pitch Fixed Speed (FPFS) Small Scale Horizontal Axis Wind Turbine (SSHAWT). Critical geometrical properties viz. Sectional Chord ci and Twist distribution θTi for the idealized, optimized and linearized blades are analytically determined for various operating conditions. Results obtained from BEM theory demonstrate that the average sectional chord ci and twist distribution θTi of the idealized blade are 20.42% and 14.08% more in comparison with optimized blade. Additionally, the employment of linearization technique further reduced the sectional chord ci and twist distribution θTi of the idealized blade by 17.9% and 14% respectively, thus achieving a viable blade bounded by the limits of economic and manufacturing constraints. Finally, the study also reveals that the iteratively reducing blade geometry has an influential effect on the solidity of the blade that in turn affects the performance of the wind turbine.

Optimal Rotary Wind Turbine Blade Modeling with Bond Graph Approach for Specific Local Sites

“…The blade element method considers that the blade is divided into N elements that are defined by radius, chord length, twist angle, and airfoil. In the blade element theory, the aerodynamic loads acting on each element are computed using the drag and lift coefficient of the airfoil [28,31,32]. The aerodynamic (lift and drag) forces applied to the ith blade elements are separated into axial F ni and tangential F ti .…”