阻抗管法测量水下吸声系数的系统误差分析*

利用阻抗管法测量吸声系数是水下吸声材料研制过程中的重要环节，实验测量结果相比理论计算结果更具说服力。然而在待测样品的制备和安装过程中容易引入的系统误差往往被忽略，从而影响实测结果可信度。为了降低系统误差，本文提出缝隙宽、垂直度和光洁度三种可能引入系统误差的因素，搭建传递函数法水下吸声系数测量的有限元模拟实验环境并验证仿真计算算法的正确性，研究相关参量对橡胶吸声系数的影响规律，并给出一定误差下对相关参量的限制要求。所得结论对降低测量误差、提升实测结果可信度具有一定参考价值。

System error analysis of underwater sound absorption coefficient measurement by impedance tube method

Measuring the sound absorption coefficient by impedance tube method is an important step in the development of underwater sound absorption materials. The experimental results are more persuasive compared with the theoretical and simulation results. However, the system errors caused during the preparation and installation of the sample is often ignored, which will affect the reliability of the experimental results. In order to reduce system errors, three possible factors that may cause system errors are proposed in this paper, including slit width, verticality and surface finish. The finite element simulation experiment environment of underwater sound absorption coefficient measurement by transfer function method is established and its correctness is verified. The influences of the related parameters on the sound absorption coefficient of rubber are studied and then the limitations of the parameters under a certain error range are given. The achieved conclusions are of reference value for reducing the measurement error and improving reliability of experimental results.