不同声强宽带噪声激励下结构参数对穿孔板消声器吸声特性影响的实验研究

高声压级激励下,由于非线性效应的存在,穿孔板消声器的吸声特性将发生改变,而改变量的大小与穿孔板的结构参数(穿孔率,孔径,板厚)密切相关。本文设计搭建了实验平台来研究结构参数的变化对穿孔板消声器的吸声特性的影响。根据实验结果发现:随着声压级的升高,由于穿孔板结构的非线性加剧,其声阻抗将发生变化,导致穿孔板消声器的吸收峰值降低,但吸收频带却拓宽了;在穿孔率一定的情况下,孔径越小的穿孔板消声器更适合低声压级环境工作;在孔径一定的情况下,穿孔率越低的穿孔板消声器也更适合低声压级环境工作。

An experimental investigation of sound absorption characteristics of a perforated plate muffler for different configuration parameters under excitation of broad-band noise of various sound intensity

With high sound pressure level excitation,the sound absorption characteristics of perforated plate muffler will change,due to the exciting nonlinearity,while the amount of sound absorption has a close relation to the perforated plate construction parameters(porosi- ty,diameter of hole,thickness of the perforated plate).In this paper,an experimental plat- form is established to study the effects of different construction parameters upon the sound absorption characteristics of perforated plate muffler.According to the experimental results, along with increase of the sound pressure level,nonlinearity of the perforated plate structure grows in intensity and its acoustic impedance changes.It decreases the value of absorption peak,while widens the absorption band.For a perforated plate muffler,if the porosity is not changed,the smaller the hole diameter,the more suitable for the lower sound pressure environment;if the hole diameter is not changed,the smaller the porosity,again the more suitable for the lower sound pressure environment.