背衬对隔声去耦瓦吸声性能的影响

基于传递矩阵法,建立了不同背衬情况下的水下隔声去耦吸声覆盖层模型,讨论了软背衬、硬背衬、单层壳体背衬和双层壳体背衬条件下隔声去耦瓦的吸声性能。结果表明:双层壳体背衬条件下吸声系数曲线存在明显的调制现象,且壳间水层增厚,吸声峰值向低频移动,峰增多、变密,峰值有所减小,而外层壳板厚度变化对吸声系数影响不大;单层壳背衬条件下,钢板的厚度越大,第一吸声峰值向低频移动,且峰值变小;当钢板的厚度达到一定的厚度时,其吸声系数曲线逐渐与刚性背衬下隔声去耦瓦的吸声曲线接近。

Effect of backing on sound absorption behavior of isolating-sound and decoupled tile

Based on the transfer matrix method, a different backing situation of underwater isolating-sound and decoupled cover model is established. The sound absorption performance of isolating-sound and deeoupled tile is discussed under soft backing, rigid backing, single-shell and double-shell backing. The results show that the absorption coefficient curve marks modulation behavior under double-shell backing, the water layer between the shells thickens and absorption peak value moves to low frequency. In addition, the number of peak increases and concentrates, the peak value also drops. The absorption coefficient is little influenced by the outer shell thickness. Under single-shell backing conditions the more the thickness of the shell plate is ,the less the first absorption peak value is, and the peak moves to lower frequency. When the plate thickness is up to a certain thickness, the absorption coefficient curve gradually approached that in rigid backing.