Aerodynamic performance of horizontal axis wind turbine with application of dolphin head-shape and lever movement of skeleton bionic airfoils

Abstract

In order to continuously develop the special airfoil for wind turbine and further improve the energy efficiency of wind turbine, based on the bionic airfoil Dol-Rot 24° that was proposed by the streamline contour of the Phocoenoides Dalli, another novel bionic airfoil is constructed combined with the lever movement shape of the dolphin skeleton, and the airfoil is named Dol-Rot 24°-2. For the cross section of NREL phase VI horizontal axis wind turbine blade (S809 airfoil), Dol-Rot 24°, and Dol-Rot 24°-2 are adopted and numerically simulated to quantitatively analyze from both aspects of aerodynamic performance and noise characteristics. Using the above two novel airfoils profiles, two 3D bionic blades named Dol-Blade-1 and Dol-Blade-2 suitable for NREL phase VI HAWT are established. The results show that: compared with S809 airfoil, Dol-Rot 24°-2 airfoil can greatly improve the lift coefficient, while Dol-Rot 24° airfoil can more effectively inhibit the flow separation on the suction surface. In terms of noise characteristics, compared with S809 airfoil, the noise of the two types of dolphin airfoils does not increase significantly. In addition, Dol-Blade-1 can comprehensively improve the low-speed shaft torque of the blade, while the load of the wind turbine hardly changes. The low-speed shaft torque of Dol-Blade-2 is even better than that of Dol-Blade-1. However, the blade root bending moment of Dol-Blade-2 increases obviously, which inevitably increases the load of the wind turbine. In this paper, the new bionic method is proposed to improve the wind energy utilization of wind turbine on the premise of strictly controlling the aerodynamic noise and load level of blade. The research results of this paper can provide a reference for the optimization of energy efficiency and noise research of NREL phase VI HAWT.