基于谱元法的复杂海洋空间甚低频声传播特征研究  

Study of very-low-frequency sound propagation characteristics in the complex ocean space based on the spectral element method

作　　者：马嗣宇 张宇翔[2,3] 谢志南 殷敬伟[2,3] MA Siyu;ZHANG Yuxiang;XIE Zhinan;YIN Jingwei(National Key Laboratory of Underwater Acoustic Technology,Harbin Engineering University,Harbin,150001;Key Laboratory for Polar Acoustics and Application of Ministry of Education,Harbin,150001;College of Underwater Acoustic Engineering,Harbin Engineering University,Harbin,150001;Key Laboratory of Earthquake Engineering and Engineering Vibration,Institute of Engineering Mechanics,China Earthquake Administration,Harbin,150080)

机构地区：[1]哈尔滨工程大学水声技术全国重点实验室,哈尔滨150001 [2]极地海洋声学与技术应用教育部重点实验室,哈尔滨150001 [3]哈尔滨工程大学水声工程学院,哈尔滨150001 [4]中国地震局工程力学研究所地震工程与工程振动重点实验室,哈尔滨150080

出　　处：《声学学报》2024年第4期844-854,共11页Acta Acustica

基　　金：国家自然科学基金项目(52171334);国家重点研发计划项目(2021YFC2801200);中央高校基本科研业务费专项资金(XK 2050021032)资助。

摘　　要：围绕甚低频水下声传播特性以及海底地形对其影响,利用谱元法开展复杂海洋空间声场仿真研究。构建了计入海底复杂流−固耦合的轴对称模型实现谱元法中的点声源激发和全波模拟。通过时域和时频域分析发现,Scholte波多次通过阶梯状上坡地形后,能量结构稳定,脉冲宽度和频带范围都没有显著变化。甚低频声波传播特性同时受整体地形和局部起伏影响。近似真实海底地形,如阶梯状地形条件下的声传播损失特性无法简单地用单一对数表达式有效描述。浅海阶梯状上坡地形软质海底中,声源接近海底时激发的界面波向远处传播的能力优于水中声波。软质海底水平海洋空间中有效激发并接收界面波模态时,整体的声传播损失近似于柱面扩展。The research on the acoustic field in the complex ocean space is carried out with the spectral element method(SEM).The study focuses on the characteristics of very-low-frequency(VLF)underwater acoustic propagation and the influence of seafloor relief on it.An axisymmetric model which takes the complex flow-solid coupling near the seafloor into account is constructed.Then the point source excitation and full-wave simulation in the SEM are realized.Through discussing in time and time-frequency domains,it is found that the energy structure of the Scholte wave is stable with no significant change in pulse width and frequency range after passing through several upstairs terrains.The propagation characteristics of VLF acoustic waves are affected by both the overall topography and local undulations.The acoustic transmission loss in almost real seafloor relief space,such as stepped terrain,cannot be effectively described by one single logarithmic expression only.In shallow sea areas with soft sediment and stepped-up topography,the interface waves excited by a sound source close to the seabed have a better ability to propagate long distances than the sound waves in the water.The overall acoustic transmission loss in the horizontal ocean space with soft sediment is approximated by the columnar expansion when the interface waves are effectively excited and received.

关 键 词：谱元法 声传播 传播损失 界面波 

分 类 号：P733.2[天文地球—物理海洋学]