Aerodynamic Noise Simulation And Noise Reduction Measures Of Wind Turbine Airfoils

With the rapid development of wind power industry,wind turbines are also moving towards large-scale development.The installed capacity of wind turbines is increasing,blade growth and tip speed ratio are increasing.And with the increase of the number of wind fields,the distance between wind turbines and residential areas decreases,which makes the noise problem prominent.Noise pollution not only has a negative impact on the ecological environment that can not be ignored,but also endangers the physical and mental health of human beings.It has attracted the attention of environmental protection organizations abroad.With the continuous improvement of computational fluid dynamics and computational aeroacoustics,numerical simulation has become an important method to study the aerodynamic noise of wind turbines.In this paper,the aerodynamic performance of DU-W-97-300 airfoil was simulated by using Fluent software.The flow field around the airfoil was obtained.Then the noise was simulated by LES/FW-H method,and the noise reduction method was studied.The results show that the leading edge and trailing edge of airfoil and separation zone are the main sources of aerodynamic noise;with the increase of angle of attack,the maximum sound pressure level decreases gradually in the low frequency band,and the total sound pressure level increases.The interaction of vortices of different sizes makes the spectrum of aerodynamic noise develop towards broadband characteristics;and at high frequency,the maximum sound pressure level decreases gradually.The aerodynamic noise of the airfoil can be reduced by controlling the angle of attack of the airfoil and setting serrated teeth on the trailing edge of the airfoil,but with the increase of the distance,the influence of changing the local shape of the airfoil on the noise becomes smaller and smaller.When the airfoil reaches a certain distance,the influence is several.Through a large number of repeated simulation calculations,the results of this paper provide a certain reference value for the aerodynamic noise analysis of wind turbine blades,and also provide a preliminary exploration for further research on noise reduction methods of wind turbine.