SET Proceedings 2978-4387 Caravel Press 10.65582/set.2011.298 2011.298 Aerodynamic Modeling of Wind Turbine Blades and Linear Approximations MirhosseiniM. m.mirhosseini@me.iut.ac.ir SedaghatA. AlemrajabiA.A. Department of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran 04092011 10 978-1-995850-03-0 1 6 4 September 2011 © 2011 Copyright WSSET 2011

In this paper, Blade Element Momentum theory (BEM) is used to design a HAWT blade for a 200 kW wind turbine. The airfoil is Risø, produced by RISØ National Laboratory, Denmark, for a class of 200KW wind turbines. Desirable properties of this airfoil are related to enhancement of aerodynamic and structure interactions. The purpose of this study is to find a simpler linear modification to the shape of blades. Design parameters considered here are wind tip speed ratio, nominal wind speed and diameter of rotor. BEM is used for obtaining maximum lift to drag ratio for each elemental constitution of the blade. Obtaining chord and twist distribution at assumed tip speed ratio of blade, the aerodynamic shape of the blade in every part is specified which correspond to maximum accessible power coefficient. In order to simplify manufacturing of the blades, a linear approximation is employed for both chord and twist distribution. The design parameters are trust coefficient, power coefficient, angle of attack, angle of relative wind, drag and lift coefficients, axial and angular induction factors. The blade design distributions are presented against rotor radius for BEM results and also compared with the linear approximation.

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