摘要:
已有对浅海低频水声场的讨论多是关注声能量在水体中的分布特性,对水体下沉积层、基底中低频声传播的同步研究相对较少。本文基于波动方程,在柱坐标系下推导了一种浅海水体/海底统一波导下低频声能流的计算模型,在此基础上结合具体仿真算例与波动理论阐述了不同沉积层声学参数对声场能量分布的影响规律及机理。仿真结果表明,在沉积层纵波声速>水中声速>沉积层横波声速的前提下,沉积层中密度与纵波声速数值越大,声能量越趋于保留在水体中而不向海底泄漏,横波声速的影响正好相反;沉积层厚度增加到一定量后,基底对流体层中声传播的影响可近似忽略不计。
Abstract:
Most existing literatures on low-frequency underwater acoustic propagation in shallow water focus on the acoustic propagation features in the water column,while studies on acoustic propagation features in the sediment layer or the semi-infinite basement are rarely.In this paper,based on the wave equation,a computational model for acoustic energy flux in the sediment layer and the basement as well as in the water column is built under cylindrical coordinates.On this basis,the effects of various sediment acoustic parameters on the acoustic energy distribution and the corresponding mechanisms are elaborated through numerical examples and acoustic theory.The simulation results reveal that,in the situation of sediment P-wave speed ＞ water sound speed ＞ sediment S-wave speed,the greater the values of density and P-wave speed in sediment,the more likely the acoustic energy remains in the water column without leaking to the ocean bottom,while the influence of the variation of S-wave speed is in the opposite way.Basement influence on the acoustic propagation in fluid layer is approximately negligible after the sedimentary layer is thickened to a certain degree.
本站查看
下载:
