基于SONAH的水平轴风力机风轮噪声源识别

Noise Source Identification About Horizontal Axis Wind Turbine Rotor Based on SONAH

将统计最优近场声全息(SONAH)技术运用于小型水平轴风力机风轮噪声源识别中,采用近场声全息技术以弥补远场波束形成技术对低频段声源识别精度低的缺点。利用B&K公司的60通道圆形声阵列对运行中的水平轴风力机在不同工况下进行声场信息采集分析,分析了噪声总声功率级的分布特征以及噪声源位置的分布规律。分析结果表明:风轮旋转时,以200 Hz以下的旋转噪声为主导,噪声源能量最大区域主要集中在叶片中部(r/R=0.5附近),并随着频率的增大,声源沿旋转面径向方向由叶片中部逐渐向叶尖分散。

The statistically optimal near-field acoustic holography(SONAH)technique is applied to noise source identification of small horizontal axis wind turbine,in order to make up for the shortcomings of the far field 'beamforming' technique on the accuracy of low frequency sound source identification.The 60 channel sector wheel array from the B & K is used to exquisite and analysis the sound field information of the operating horizontal axis wind turbine at different conditions.The characteristics of total sound power levels and noise source distribution is analyed.The results showed that:Dominated by rotating noise below 200 Hz when the wind rotor rotating.The largest regional of noise sources are mainly concentrated in the middle of the blade(approximately 35 cm from the tip position),and with increasing frequency,the sound source disperse gradually from the middle to tip of the blade along the radial direction in the rotation surface.