近场声全息方法识别噪声源的实验研究

根据近场声全息(NAH)的原理，建立了全息实验所需要的采集、分析系统。针对影响重建精度较大的截止波数的选取问题，给出了较为详细的讨论．并提出一种不需先验知识的截止波数选取方法。最后通过对实测数据进行全息变换．重建结果表明：在采用提出的截止滤波选取方法后，NAH技术可以精确地对噪声源进行定位与识别，并且可以得到三维空间内的声压、质点振速和声强矢量等声学信息。

Experimental Research on Noise Source Identification Using Near-Field Acoustic Holography Method

According to the principle of near-field acoustic holography (NAH), the system of data acquisition and analysis needed in holographic experiments have been constructed. By analyzing the method to determine the cut-off wave number that plays an important role for reconstruction precision, a novel method without prior knowledge has been developed to determine the cut-off wave number. The reconstructed results using experimental data show that NAH can be applied to identify and localize the noise sources precisely by adopting the cut-off wave number determining method proposed; moreover, acoustic information such as sound pressure, particle velocity and sound intensity of the whole three-dimensional field can be obtained correctly.