复合材料吸声系数的理论计算及性能分析

不同噪声环境中的降噪需求不同,为根据噪声频谱合理设计复合吸声材料,基于穿孔板及多孔吸声材料的吸声原理,提出了改进的声-电类比法,推导出复合吸声材料吸声系数的理论计算公式.利用该种计算方法,通过数值仿真深入分析复合吸声材料内外层穿孔率,多孔材料厚度,空腔变化对吸声性能的影响,分析表明第1层板穿孔率及多孔材料厚度影响较大.最后用声学实验对计算结果进行验证,表明改进的声-电类比法有效.

Theoretical calculation and performance analysis of the absorption coefficient of composite materials

The noise-reduction needs in different noise environment are different. In order to design composite sound absorption material reasonably according to the noise spectrum, based on the sound absorption principle of perforated plate and porous sound absorption material, the improved acoustic-electro analogy method was derived. Using this methodthe ab-sorption coefficient of the compound sound absorption structure was calculated. Through numerical simulation the influence of perforation rate inner and outer layers, the porous material thickness, and cavity size on sound absorption properties has been analyzed profoundly. The analysis shows that the perforation rate of the first plate and the porous material thickness have obvious influence. And the results were verified by the acoustic experiment. The results showed that the improved acoustic-electro analogy method was feasible.