Bionic design of winged seed's aerodynamic force characteristics apply to wind turbine blades

Abstract

In the present study, the wing of the seed of the green maple (Acer serrulatum) was used as the imitated object, and the shape of the seed wing was analyzed. The study and design of the bionic wind turbine blade were then progressed by the ANSYS Fluent simulation software to perform the numerical computations of the aerodynamic and flow characteristics of the seed wing of the green maple. Also, based on the scale up contour of the seed wing of the green maple, a set of bionic blades was fabricated to build a small scale horizontal axis wind turbines (HAWT) with either three-blade or five-blade configuration. The turbine was tested in a wind tunnel to explore the correspondence between aerodynamic characteristics and the wind/electricity power transform efficiency. The numerical results, by an inspection of the trend of the lift coefficient curves, indicated that the seed wing of the green maple has larger range of angle of attack, 0° to 50°, without stall, which shows an aerodynamic advantage. In addition, the wind tunnel experiments of the wind turbine, with 5 bionic blades, 0.237583 m2 swept area, 15° angle of attack, and 5 m/s steady head wind conditions, showed that the highest wind/electricity power transform efficiency can be reached up to 37%.