Effects of trailing-edge movable flap on aerodynamic performance and noise characteristics of VAWT

Efficiency enhancement and noise reduction are the two critical factors in the wind turbine design. In this paper, the effects of trailing-edge flap on the aerodynamic performance and noise characteristics of NACA0018 airfoil and vertical axis wind turbine (VAWT) were investigated, and the geometric parameters including flap angle, flap position and flap length were considered. The aerodynamic performance was simulated with the Detached-Eddy Simulation (DES) based on Spalart-Allmaras turbulence model and noise characteristics is calculated by CFD combined with Ffowcs-Williams and Hawkings (FW-H) acoustic analogy method. The research results indicate that the trailing-edge flap could effectively suppress flow separation and reduce the airfoil noise at high angle of attack (AOA). The optimum flap parameters obtained by orthogonal experimental design (OED) method were applied in VAWT, and it was observed that the trailing-edge flap could significantly improve the power coefficient at high tip-speed ratio (TSR) and reduce the VAWT noise. The research in this paper provided a comprehensive reference for improving the dynamic stall characteristics and reducing the noise of VAWT in practical engineering applications. •The effects of trailing-edge flap on the airfoil and VAWT were investigation.•The aerodynamic performance and noise characteristics were considered in this paper.•The Orthogonal Design method was used in the optimization of flap geometric parameters.•A motion control strategy of trailing-edge flap used in VAWT was proposed.