不同界面形状分层消声覆盖层声特性的实验研究

研究了不同界面形状的分层消声覆盖层的吸声性能。制备了三角形、半圆形、矩形和平面形等不同界面形状的分层消声覆盖层,并在声管中测试了其水声吸声系数。结果表明:在研究的频率范围内,非平面界面形状的分层消声覆盖层吸声性能优于平面界面形状的分层消声覆盖层的吸声性能,其中,半圆形界面形状的分层消声覆盖层吸声效果最好。原因在于声波在非平面界面上会发生波型转化,使声衰减能力弱的纵波转化为声衰减能力强的切变波,引起较大的剪切变形,入射波能量被大量地消耗。研究说明,合理设计分层消声覆盖层界面形状可以提高其水声吸声性能。

Experimental study on acoustic characteristics of multiplayer anechoic coatings with different interfaces

We study sound absorption properties of anechoic coatings with different interface shapes. The anechoic coatings with triangle, semicircle, convex rectangle and plate interface shapes were prepared and their underwater sound absorption coefficients measured in a sound tube. The results show that absorp-tion coefficients of the absorbers with single-layer non-planar interface are higher than that with planar interface shapes. In the investigated frequency range, the semicircle interface shape is the best in terms of absorption. It is also found that, at low frequencies, absorption coefficients of absorbers with doublelayer non-planar interface are obviously higher than that with planar interface. The increase of absorption of the anechoic coatings with non-planar interface shapes results from wave conversion of the incident longitudinal wave into shear waves. It is therefore suggested that appropriate design of the interface shapes of the anechoic coatings can enhance underwater sound absorption properties.