Section of Acoustics, Aalborg University, Fredrik Bajers Vej 7-B5, DK-9220 Aalborg Ø, Denmark.
J Acoust Soc Am. 2011 Jun;129(6):3727-44. doi: 10.1121/1.3543957.
As wind turbines get larger, worries have emerged that the turbine noise would move down in frequency and that the low-frequency noise would cause annoyance for the neighbors. The noise emission from 48 wind turbines with nominal electric power up to 3.6 MW is analyzed and discussed. The relative amount of low-frequency noise is higher for large turbines (2.3-3.6 MW) than for small turbines (≤ 2 MW), and the difference is statistically significant. The difference can also be expressed as a downward shift of the spectrum of approximately one-third of an octave. A further shift of similar size is suggested for future turbines in the 10-MW range. Due to the air absorption, the higher low-frequency content becomes even more pronounced, when sound pressure levels in relevant neighbor distances are considered. Even when A-weighted levels are considered, a substantial part of the noise is at low frequencies, and for several of the investigated large turbines, the one-third-octave band with the highest level is at or below 250 Hz. It is thus beyond any doubt that the low-frequency part of the spectrum plays an important role in the noise at the neighbors.
随着风力涡轮机变得越来越大，人们开始担心涡轮机的噪声会向低频移动，从而给邻居带来烦恼。本文分析和讨论了额定功率高达 3.6MW 的 48 台风力涡轮机的噪声排放情况。对于大型涡轮机（2.3-3.6MW），低频噪声的相对比例高于小型涡轮机（≤2MW），且差异具有统计学意义。这种差异也可以表示为频谱向下移动约三分之一个倍频程。对于未来 10MW 范围内的涡轮机，建议进行类似大小的进一步移动。由于空气吸收，当考虑相关邻居距离处的声压级时，低频内容的比例更高。即使考虑 A 加权级，噪声的很大一部分仍处于低频，对于一些调查的大型涡轮机，最高级别的三分之一倍频带处于或低于 250Hz。因此，可以毫无疑问地说，频谱的低频部分在邻居的噪声中起着重要作用。
