基于Sobol灵敏度分析法的风电机组噪声特性研究

Noise characteristics of wind turbine based on Sobol sensitivity analysis

风电机组所产生的噪声主要来自于由其叶片引起的气动噪声,包括来流湍流噪声和翼型自身噪声两部分,目前已成为影响声环境的重要因素之一。本文以Amiet&Lowson半经验风电机组噪声预测模型为研究对象,通过引入Sobol全局灵敏度分析方法,探究了影响风电机组来流湍流噪声各因素的重要性。研究表明,影响风电机组噪声大小的因素依次为:来流速度、声源到观测点的距离、声波频率、翼型弦长、翼型展长、空气密度和翼段距离地面高度,其中来流速度为最主要因素,其次为声源到观测点距离和声波频率,以上三点因素与风电机组结构无关,表明改变风电机组结构对缓解噪声污染效果不大。对于风电机组本身结构而言,翼段弦长的影响最大,如需要通过结构的改变来降噪,此参数应该为最先考虑的对象,其次为翼型展长。

The noise generated by wind turbine mainly comes from the aerodynamic noise caused by its blades,including incoming turbulence noise and airfoil noise,which has become one of the important factors affecting the acoustic environment.In this paper,Amiet&Lowson semi-empirical wind turbine noise prediction model is used as the research object,and Sobol global sensitivity analysis method is introduced to explore the importance of each factor affecting the turbulence noise of wind turbines.The research shows that the factors affecting the noise of wind turbines are as follows:Incoming flow velocity,distance from the sound source to the observation point,acoustic wave frequency,airfoil chord length,airfoil spread length,air density and the height of the wing segment from the ground,among which the incoming flow velocity is the most important factor,followed by the distance from the sound source to the observation point and the acoustic wave frequency.The above three factors have nothing to do with the wind turbine structure,indicating that changing the wind turbine structure has little effect on alleviating noise pollution.For the structure of the wind turbine itself,the chord length of the wing segment has the greatest impact.If noise re duction is required through structural changes,this parameter should be the first object to be considered,followed by the airfoil spread length.