基于分布源边界点法的近场声全息实验研究

采用基于分布源边界点法的近场声全息技术对运转状态下的罗茨真空泵进行了噪声源识别和定位研究。实验采用13个声压传感器组成的传声器阵列和1个参考传声器测量全息面上的复声压信息，进而通过基于分布源边界点法的近场声全息技术和Tikhonov正则化方法重建获得声源的表面法向振速。重建结果表明：在测量信号中存在的2个低频噪声是支架在真空泵振动的激励作用下产生共振所致，而非真空泵本身所固有的噪声；而1533．2～1699．2Hz的宽带噪声则是真空泵端盖表面振动所产生，是真空泵所固有的噪声。同时，重建结果给出了各频率处噪声源的具体位置，为有效地进行真空泵的噪声控制提供了依据。

An experimental study on the distributed source boundary point method based nearfield acoustic holography

The distributed source boundary point method(DSBPM) based nearfield acoustic holography(NAH) is used for identifying and localizing noise sources of the roots vacuum pump.The complex acoustic pressures on the hologram surface closed to the sources are obtained by a microphone array scanning step by step and a reference microphone.The DSBPM based NAH are used to reconstruct the normal surface velocities,and the Tikhonov regularization method is used to regularize the reconstructed solutions.The reconstructed results show that,the two low frequency noises in the acoustic field are not inherent in the roots vacuum pump but generated by the supports under excitation of the vibration of the pump,however,the wideband noise with the frequency range from 1533.2Hz to 1699.2Hz is generated by one of the end surfaces of the roots vacuum pump and is the inherent noise of the roots vacuum pump.Additionally,the reconstructed results show the positions of every noise sources distinctly,and it is helpful for the noise control of the roots vacuum pump.