Aerodynamic characteristics of wind turbine blades with a sinusoidal leading edge

The aerodynamic characteristics of a kind of bionic wind turbine blades with a sinusoidal leading edge have been investigated in this paper based on a three-dimensional Reynolds-averaged Navier–Stokes simulation. The calculated results show that compared with a straight leading-edge blade, the new-type blade has a great improvement in shaft torque at high wind speeds. The localized vortices shedding from the leading-edge tubercles, which can generate a much greater peak of the leading-edge suction pressure than that from the straight leading-edge case, are the physical essentials to enhance the wavy blade's aerodynamic performances as the blade goes into stall. In particular, the outboard segment from the 60%R station to the blade tip is the key region for wavy leading-edge blades to improve the aerodynamic characteristics at high-speed inflows. In this key region, a wavy blade can obtain a greater power output as the wavelength l and the waveheight δ increase. The present numerical results also show that the wavy leading-edge shape is unfavorable for a wind turbine blade under the design conditions (e.g., at the rated wind speed). At these conditions, an early boundary-layer separation as a result of the geometric disturbances of the leading-edge tubercles will inevitably result in a visible shaft-torque reduction in the wavy-blade cases. Anyway, the wavy blades still tend to generate a more robust power output as a whole from 10 to 20 m s −1 than the original NREL phase-VI blade. Copyright © 2011 John Wiley & Sons, Ltd.