Abstract:

The aerodynamic noise of wind turbines mainly concentrate in low-frequency range, with small corresponding air absorption coefficient. The noise is mainly caused by the friction between the rotating wind turbine blades and the air, and is greatly related to the parameters such as the surface and angle of the wind turbine blades. In this paper, the flow field surrounding the symmetrical airfoils in Large Eddy Simulation (LES) model was computed by finite element method; the sound field of the aerodynamic noise was simulated by Lighthill acoustic analogy method; aerodynamic characteristics and sound pressure levels at the monitoring points were compared with the experiment results, which showed that they were almost identical. To eliminate the influences of boundary conditions, actual situations use High Reynolds number, low Mach number, frequency domain boundary stationary FW-H equation, and the influence of non-compact Green’s boundary was considered to compare the value results of sound pressure acquired from FFT conversion and the analytical results, which showed that the two results were identical. This research has special value and can provide references for designing the airfoil profiles of wind turbines in future.

Keywords: