方波扫描路径确定声源声功率误差特性分析

Error Characteristics of Determining Sound Power by Using the Orthogonal Scanning Path

改进了矩形测量面方波扫描路径测量声功率的误差模型 ,以单极子、偶极子及四极子声源为例 ,给出了扫描方向、测量面离声源的距离及扫描线的密度的选取对理论误差的分布图形。分析结果表明 :对选定的测量面 ,在扫描线密度小的情况下 ,通过调整声源离测量面的距离 ,可以在声源近处找到一个最优点或较优点 ,使理论误差为零或很小 ;在绝大多数情况下 ,沿测量面长边扫描误差比沿短边扫描小。

The error model in sound power measurement by using the rectangular scanning surface and the orthogonal scanning path is improved. The relationship between the choices of the scanning direction, the distance between the measuring surface and the sound source, the density of the scanning lines and their errors are given on the distribution figures. The monopole, dipole and quadrupole sound sources are investigated as example. The results show that, to a given measuring surface, if the density of the scanning lines is small, error may be decrease to zero or a very small value by modified the distance between the measuring surface and the sound source. In most cases, the error scanning along the longer side of the rectangle is smaller than that along the shorter side.