小型垂直轴风力发电机的气动噪声数值模拟与试验验证

为了降低小型垂直轴风力发电机的气动噪声,对其噪声产生机理进行了分析。首先,在瞬态计算时运用大涡模拟(LES)模型对在一定工况下的三维风轮周围的流场进行分析;其次,在声学计算时运用FW-H方程对风轮产生的气动噪声进行分析并得出频谱;最后,通过实例验证了该方法能有效预测其气动噪声。结果表明:小型垂直轴风力发电机的气动噪声主要是涡流噪声;监测点的噪声值随着离风轮旋转轴半径的增加而减小,且在垂直于叶轮旋转轴的平面上具有指向性。小型垂直轴风力发电机的气动噪声分析为其进一步低噪声优化提供了依据。

Numerical Simulation and Analysis of Aerodynamic Noise Based on Small Vertical Axis Wind Turbine

The mechanism of the noise produced by the small vertical axis wind turbine is analyzed in order to reduce its aerodynamic noise. At first,in the transient calculation,the large eddy simulation( LES) model is used to analyze the flow field around the three dimensional wind wheels under a certain working condition;Secondly,in the acoustic calculation,the FW-H equation is used to analyze the aerodynamic noise generated by the wind wheels in order to get the spectrum. Finally,the method is proved to be effective in predicting the aerodynamic noise. The results show that the aerodynamic noise produced by the small vertical axis wind turbine is mainly the vortex noise;the peak value of sound pressure level decreases with the increase of the radius of the rotation axis of the wind wheel;and its noise has the directivity at the plane perpendicular to the rotation axis of the impeller. The aerodynamic noise analysis of small vertical axis wind turbine provides the basis for the optimization of its low noise.