线列阵管中校准方法研究

A Study of Calibrating Line Array in a Chamber

本文提出了一种在密闭管中测量线阵的自由场复数灵敏度和指向性图的方法。在管中沿管轴方向布置一系列发射换能器和监测水听器 ,根据实测得到的传递函数矩阵和所要模拟的平面波频率、幅度和入射角计算得到一组发射换能器驱动信号的幅度和相位 ,然后以此信号激励每个发射换能器 ,就能在管中形成一个等同于任意角度入射的自由场平面波声场的声压分布。已经开发了一个初型实验系统 ,系统频率范围 2 0～ 6 0 0Hz 。

In this paper,a closed chamber technique for measuring the complex free field sensitivity and directivity patterns of line array is described.Projectors and monitoring hydrophones are placed in a chamber along its length.The projectors are driven by the required drives that are calculated according to a measured transfer matrix,and amplitude,frequency and incident of the predicted plane wave.Then the acoustic pressure field distribution which is equivalent to the predicted plane wave of any incidence is set up in the chamber.A prototype calilbration system has been developed.The system can operate over the frequency range from 20 to 600 Hz.The measurement results obtained in the chamber have shown in a good agreement with the theoretical predicted curves.