典型声源声聚焦引起辐射噪声测量误差的分析

Error Analysis in Radiated Noise Measurement Due to Acoustic Focusing of Typical Sound Sources

随着影响目标辐射噪声测量诸多因素的解决,声聚焦对测量精度的影响已显得比较突出。基于射线声学的虚源法,通过具体算例,分析了典型声源声聚焦引起的测量误差。仿真结果表明,声聚焦引起测量误差的大小与声源的类型、辐射指向性,边界约束,声源和接收器的空间位置,信号带宽、频率均有关。因此,传统的利用球面波规律对不同类型的声源辐射声测量值进行归一是有偏差的,需根据声源的辐射指向性及相关参数进行特定的修正。

The influence on measurement precision by acoustic focusing has become obvious because of the solution of other relevant elements in radiated noise measurement. Here the measurement errors due to acoustic focusing of typical sound sources are analyzed by detailed examples based on the method of image sources in the Ray Theory. The simulation results show the measurement errors due to acoustic focusing are relevant to the type and the radiation directivity of the sound sources, boundary constraint, the spatial location of sound sources and receivers, and the band width and frequency of the signals. Therefore, the traditional spherical wave law in the normalization of the measured data has to be improved according to the directivity of the sound sources and other parameters.