颗粒浓度对声屏蔽装置吸声性能的影响

Affection to sound absorption of sound shield device from density of elastic particles

吸声一直是声学界研究的热点问题,声屏蔽装置是一种有效的水下噪声吸收装置。针对声屏蔽装置的声散射特性进行了分析,采用吸声颗粒悬浮层作为研究对象,对吸声悬浮层的衰减系数进行探讨,重点讨论了不同浓度的悬浮层对不同频率声波的吸声系数的影响。针对稀浓悬浮层,采用考虑颗粒之间影响和不考虑颗粒之间影响2种方式进行了理论分析与计算,分析结果认为:从5 000～6 000 Hz声波频率对悬浮层吸声效果影响并不明显,高于6 000 Hz,声波频率的影响开始明显;增加悬浮层的浓度对于吸声效果影响非常明显。就声屏蔽装置而言,在参考不同浓度对不同频率声波的影响基础上,通过合理的计算,可以得出喷射装置的管径、流量与速度。

Sound absorption is a hot topic in the field of underwater acousitcs, and acousitic shielding device is an effective device to absorb underwater acoustic. In this paper,the elasitic suspension layer was main subject of our research, the character of sound scattering of this device was analysed, the coefficient of sound absorption of suspension layer had been discussed, the affection of sound absorption coefficient had been disscussed, from different density of particles to different frequency wave. Two different models had been calculated and analysed theoretically, the thin and thick suspension layers, the interaction of the particles was taken into consideration for the thick layer, while the thin layer was not from above discussion, we can find that in frequency band of 5 000 Hz to 6 000 Hz, the effect of frequency could be ignored ;and in higer frequency band, the effect of frequency must be considered. The effect to absorbing sound from the density of particles is obvious. So in the design period, the sound frequency and the density must be taken into consideration.