基于混合波叠加法的声源识别理论与试验研究

波叠加法作为噪声源识别的一种技术，克服了基于边界元法的声全息中的奇异值积分和解的非唯一性难题，但在测量面上要求足够多的传声器数目以满足重建精度，这样导致测量成本高、工作耗时且也不利实际实施。针对波叠加法的此缺点，提出将波叠加法和HELS方法相结合的方法，此法是基于Helmholtz方程最小二乘法，用相对少量的测点数据获得包围源的最小球面上或之外的任意一假想球面上的声压数据，然后将这些数据作为输入，计算出辐射体内混合内域虚源强的强度值，通过解离散波叠加的方程，重建出在重建面上离散点的声压值。达到用相对少量的测点数据重建表面为任意形状的振源辐射声压的目的。数值仿真与试验结果表明：它具有计算速度快、重建精度高、测量成本低和容易实施等优点，可以精确地识别和定位机械噪声源，在工程实践中具有广泛的应用前景。

Theoretical and Experimental Study on Sound Source Identification Based on Combined Wave Superposition Method

The wave superposition is based on the idea that an acoustic radiator can be approximately represented by sum of fields caused by a finite number of interior point sources.But in practice,a large number of measurements must be made in order to achieve a desired resolution,which makes the reconstruction process very time consuming and high cost.Here,the combined wave superposition method is proposed to be a transform algorithm of acoustic holography.The first step in the combined wave superposition method is to establish the HELS formulations based on a finite number of acoustic pressure measurements taken on or beyond a hypothetical spherical surface that encloses a vibrating structure.Then enough field acoustic pressures are generated using HELS formulations and taken as input to Helmholtz integral formulations based on the wave superposition.The acoustic pressures at the discretized nodes on reconstructed surface are computed by solving the interior source strength.This method allows reconstruction of the acoustic field from an arbitrary object with relatively few measurements.Numerical simulation and experimental results show that sound sources can be identified and localized by this method,and it avoids reconstruction processes very time consuming and high cost thus significantly enhances reconstruction efficiency,it may become a powerful noise diagnosis tool in engineering.