半自由场波叠加噪声源识别方法研究

提出了一种适合半自由场条件下进行噪声源识别的方法，通过仿真和实验验证了半自由场波叠加噪声源识别方法的正确性。根据波叠加方法的原理，声源产生的空间声场可以用其内部的一系列虚源点来等效代替，而虚源源强可以通过匹配场点的声压来获得，进而由这些虚源重建任意场点的各种声学量。通过阵列获取声压场，结果表示成声压等值线图、三维视图或声强矢量图，便于直观地判别出声源的位置、大小和传播路径。半自由场渡叠加噪声源识剐方法可以在半自由场条件下对任意形状物体进行噪声源识别。

Study of Noise Source Identification Technique in Half-space Based on the Wave Superposition Method

An efficient NSI(noise source identification) technique in semi-free field based on WSM(Wave Superposition Method) was proposed and its validity had been examined by simulations and experiments.According to the theory of WSM,the total acoustic field radiated by an arbitrary-shaped noise radiator can be substituted by a serial of virtual source points.These point sources located on a surface interior to a body of the radiator,and their strengths can be evaluated in terms of a pressure measurement on another surface.Once calculated,the strengths of these point sources allowed the pressure(and intensity,instantaneous point velocity,etc.) distribution exterior to the radiator to be calculated.The pressure was measured with an advanced microphone array,and the final results were visualized in terms of pressure contours and instantaneous point velocity animations,etc.With these visualized maps,the main noise sources can be easily located and quantified,also the noise transmission path can be found.Through simulations and experiments,the validity and efficiency of this technique are tested.