水下非均匀复合层结构吸声的理论研究

Investigation of the sound absorption of non-homogeneous composite multiple-layer structures in water

本文对水下非均匀阻尼板与多层介质组成的吸声结构进行了研究．基于非均匀波导理论，导出非均匀钻孔阻尼层的传递矩阵及多层结构表面反声、吸声系数．对任意非均匀层，提出分层近似求传递矩阵的方法．数值计算研究了结构反声、吸声性能及其随各参数的变化．

In this paper, underwater non-homogeneous composite multiple-layer suond absorption structures are studied. The structures are composed of a non-homogeneous ab sorbent plate and some homogeneous plates of other materials. Based on the theory of non-uniform wave guide, we obtain the transfer matrix of the absorbent plate with pin holes of varying corss-section. And then the responses of sound reflection and absorption at the surfaces of the structures in water are deduced.For an arbitrary non-homogeneous plate, we propose a method to deduce its transfer matrix by dividing it into sequence of layers. By numerical calculation, the variation of the responses of reflection and absorp tion of the structures with the parameters of layers is analysed.