Simulation Study On Aerodynamic Noise Characteristics And Noise Reduction Methods For Wind Turbine Blades

Wind energy has the characteristics of randomness and volatility.With the large-scale development and construction of wind farms and the large-scale development and construction of wind farms,people gradually begin to pay attention to their impact on the environment,and the aerodynamic noise problems of wind turbine blades become more prominent.The noise caused by wind turbines has become a challenge for designers and manufacturers of wind turbines.Therefore,analyzing the mechanism and distribution characteristics of blade aerodynamic noise and the noise reduction method of blades is an important topic,which can provide reliable data support for wind turbine design and manufacture,thus contributing to the research of wind turbine noise reduction technology.First,the simulation of S809 airfoil by FLUENT is used to analyze the characteristics of the static pressure,dynamic pressure,flow velocity,eddy current and sound field around the airfoil.Analysis of the characteristics of flow field and acoustic field and aerodynamic noise characteristics using S809 2D airfoil,the analysis in the double chord,0 degree angle of attack two times chord position show directivity of the quadrupole source,angle of attack and other position pressure presents a dipole source airfoil.At the same time,the noise characteristics of the three locations and the contribution of each location to the total noise are analyzed.The noise contribution from the upper and the lower surfaces is the largest,and the noise at the trailing edge is the next.The noise from the leading edge contributes the least to the noise of the airfoil.Secondly,by analyzing the flow field and acoustic field of three different airfoil models with different trailing edge shapes at different attack angles,it is concluded that the noise of the saw tooth airfoils at different attack angles is almost lower than that of the prototype airfoil noise,which indicates that the serrated airfoil has better noise reduction effect.The wavy airfoil has smaller noise than the prototype airfoil and serrated airfoil at 0 degree-11 degrees.When it is 15 degree,its noise is larger than that of the prototype and saw toothed airfoil models.When it is 19 degrees,its noise is smaller than that of the prototype model,and the noise is larger than that of the saw toothed airfoil.It is shown that under the small attack angle,the saw tooth and wavy airfoil has better noise reduction effect,and the effect of the wavy airfoil is more.The noise reduction effect of the saw tooth airfoil is better at large attack angle.