Performance of a Small Horizontal Axis Wind Turbine with Blade Pitching
Yasser El-Okda, Mohamed S. Emeara, Nazar Abdelkarim, Kamel Adref, Hussni Al Hajjar
Abstract
In the current work, the blade element momentum theory (BEMT) is used to design small horizontal axis wind turbines (HAWT) and to examine the performance of small HAWTs with blade pitching. In the design of optimum rotor, BEMT is employed in conjunction with Schmitz formulas for three-bladed and five-bladed small HAWTs. In the current study, we used the SG6043 airfoil. A low design wind speed of 6 m/s was employed. A MATLAB code was developed to iteratively calculate the chord length and angle of twist distributions over the blade elements. Blade element momentum theory is also used to study the effect of blade pitching for a range of off-design wind speeds. Blade pitching for small HAWTs is found to improve the maximum exhibited power coefficient (C <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</inf> ) for wind speeds far from the design wind speed and has negligible effect on C <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</inf> around the design wind speed.