Aerodynamic Shape Optimization through Parametric Study using Computational Fluid Dynamics Analysis on the Small Wind Turbine Blade

The aim of this work is to find out the optimum twist angle of small wind turbine blade so as to increase its Annual Energy Production (AEP) by the means of increasing lift force on the blade of turbine in static flow condition. A horizontal-axis wind turbine (HAWT) blade is selected for optimization using an estimate code based on the Blade Element Momentum (BEM) theory. AirfoilsSG6043, BW3 and A18 are selected and utilized as candidates for designing of the micro blades. Blade element momentum theory is used to design the blade 3D geometry in the referred literature. The efficient performance of a wind turbine largely depends on the wind characteristics of the site in conjunction with the aerodynamic shape of the blades. The blade geometry will determine the torque overcome and the power generated by the rotor. By aerodynamic point of view, an economic and efficient blade design is attained by the maximization of rotor power coefficient. Some factors are different for small wind turbine blade design, than large blade. Such as, the small blades experience much lower Reynolds number flow than the large blades, hence large wind turbine airfoils may perform very poorly in small applications. The small turbines can be self-started at wind speeds which are lower, therefore the hub and tip parts are critical for the starting torque which should be able to overcome the resistance of the generator and the mechanical system. Furthermore, a well-designed wind turbine with a low cost of energy will always have an aerodynamically efficient blade. Therefore, the blade design is an important part in the whole design procedure of a wind turbine. In the current study, the objective function is restricted to the cost from the blade which is done by selecting the micro wind turbine profile, performing CFD analysis on the profile with different twist angles and analyzing the results of Lift force for the same. It is observed in CFD results of the blade that 25 degree shows most promising results in the field of lift force.