基于SONAH的旋转风轮声源识别实验研究

EXPERIMENT ON SOUND SOURCE IDENTIFICATION OF ROTATING ROTOR BASED ON SONAH

在风洞开口实验段,针对不同风速及不同叶尖速比,应用Brükel&Kjær公司60通道轮型声阵列及声信号采集系统对直径为1.4 m的S翼型风轮进行声场测试,并采用统计最优近场声全息(SONAH)技术进行旋转风轮低频噪声源识别及频域特征分析。实验结果表明:最大声强度是旋转叶片产生的基频噪声,其对应总声压级随风速增加呈函数f(x)=-0.0092x^(4)+0.297x^(3)-3.7403x^(2)+23.186x+49.274增加,随叶尖速比增加呈函数f(x)=0.4467x^(4)-10.273x^(3)+87.728x^(2)-328.75x+567.23增加;识别的噪声源最大能量中心集中于翼展位置约0.545 m,相对半径r/R=0.778处,且不随风速和尖速比的改变而改变。

In the open section of the wind tunnel,the sound field of S-wing rotating rotor with1.4-meter diameter was measured by BK60-channel type acoustic array and acoustic signals at different wind speed and different tip speed ratio was acquired.Low-frequency sound sources of rotating wind turbine were located using statistically optimal near-field acoustic holography(SONAH).The experimental results showed that the maximum sound intensity is the fundamental frequency noise generated by the rotating blades,and the corresponding sound pressure level increased as a function f(x)=-0.0092 x^(4)+0.297 x^(3)-3.7403 x^(2)+23.186 x+49.274 with the wind speed,and increased as a function f(x)=0.4467 x^(4)-10.273 x^(3)+87.728 x^(2)-328.75 x+567.23 with the tip speed ratio.The center of the identified noise sources is concentrated on the radial position of about 0.545 m,that is r/R=0.778,and did not change with wind speed and tip speed ratio.