Bionic coupling design and aerodynamic analysis of horizontal axis wind turbine blades

Abstract

With millions of years of evolution, owls have developed many excellent characteristics in terms of their flight. The speed of an owl in flight is similar to the relative speed of the blade of a small wind turbine with respect to air. Therefore, the owl wing airfoil is selected as the design airfoil of the wind turbine blade to reduce the flow separation under low Reynolds number. In this study, we analyze an owl wing‐section airfoil and the non‐smooth leading‐edge shape of an owl's wing, and implement an orthogonal optimum design to optimize the wavelength and amplitude of the non‐smooth leading edge. We extract the cross‐sectional features of the airfoil and the non‐smooth leading‐edge shape of the wing. Based on the orthogonal optimum design results, we determine the optimal combination of the wavelength, amplitude, and airfoil, and then design a horizontal‐axis wind turbine blade through bionic coupling. The flow field at different tip speed ratios (TSRs) is simulated using the turbulence model at the rated wind speed. The results show that the power coefficient () of the bionic wind turbine at a high tip speed ratio is 17.7% higher than that of the standard type. Furthermore, we analyze the operation of the turbine at TSRs of 2 and 5. At a high TSR, the leading edge bulge of the bionic wind turbine blade can change the flow direction distribution of the airflow on the blade surface, make the airflow to adhere to the suction surface, and then reduce the stall area on the suction surface of the blade. Thus, the wind turbine produces higher torque, thereby generating higher power.

Nature-Inspired Designs in Wind Energy: A Review

“…Owls require a significant amount of lift to glide silently and evade detection by their prey. As a result, the airfoil structure of owl wings has been extracted and applied in the design of wind turbine blades to enhance their performance [177].…”

“…The study revealed several remarkable features of owl feathers, including a comb-like structure along the leading edge, a fringe-like arrangement along the trailing edge, and soft down feathers on the wings and legs. These unique feather structures enable owls to glide and fly silently, setting them apart from other birds [177]. Ito [179] studied the aerodynamic influence of leading-edge serrations on an airfoil at low Reynolds numbers.…”

“…The study concluded that the owl-inspired airfoil with inlets showed promising potential for noise reduction. The investigation by Chen et al [177] focused on the bionic coupling design and aerodynamic analysis of HAWT blades. The study aimed to optimize the design of wind turbine blades by drawing inspiration from the flight characteristics of owls.…”

Enhancing Efficiency and Reliability of Tidal Stream Energy Conversion through Swept-Blade Design

“…In recent years, biomimetic technologies inspired by various biological characteristics have emerged as promising approaches for enhancing wind turbine blade design [15]. For example, to reduce the flow separation on blade surfaces, an owl wing-section airfoil and the non-smooth leading-edge shape of owl wings were studied in [16], finding that the power coefficient of the wind turbine can be increased by 17.7% by optimizing the wavelength and amplitude of the non-smooth leading edge of the blade. Inspired by the distinctive profile of the owl wing and the herringbone groove feature of owl feathers, the blade of a 200 W horizontal axis wind turbine was redesigned [17].…”