海洋声传播问题的有限元算法研究

发布时间：2018-06-19 21:02

本文选题：有限元 + 海洋声传播　；参考：《哈尔滨工程大学》2016年硕士论文

【摘要】：以有限元法为代表的数值计算方法能够用于不规则海底粗糙海面边界和不均匀海水介质等复杂海洋环境下的声传播问题,在水下声场计算和特性分析方面受到越来越多的关注。本论文从有限元算法求解波动方程的基本理论推导开始,以通用型有限元软件Comsol Multiphysics 5.0中的声学模块为仿真平台,建立低频点源声传播模型,实现基于有限元算法的声场计算。二维声传播研究中,标准楔形流体海底波导问题一直被用做检验声传播模型准确与否的基本模型。本文首先建立流体海底COMSOL模型,通过比对表明了 COMSOL模型有限元结果的准确性;接着建模仿真弹性海底情况下低频点源的声传播情况,综合对比分析了剪切波对声传播的影响以及传播过程中出现的界面波现象。实际海洋声传播环境为空间变化的三维环境,本文将COMSOL模型推广到三维理想波导并对传播特性做了分析。除上述内容以外,本文还分别对COMSOL软件在二维和三维模型中的计算效率和计算机硬件消耗做了对比,研究了 PML的最佳适用范围,并通过软件提供的APP开发器建立了三维水平理想波导的声场模型APP应用,为以COMSOL为代表的商业有限元软件更好地应用于实际声传播问题提供了新思路。
[Abstract]:The numerical method represented by finite element method (FEM) can be applied to the acoustic propagation in complex marine environments such as irregular seabed rough sea surface boundary and inhomogeneous seawater medium. More and more attention has been paid to the underwater acoustic field calculation and characteristic analysis. Starting from the basic theory of solving wave equation by finite element method, the acoustic module in Comsol Multiphysics 5.0 is used as the simulation platform, and the acoustic propagation model of low frequency point source is established, and the sound field calculation based on finite element algorithm is realized in this paper. In the study of two-dimensional acoustic propagation, the problem of standard wedge-shaped fluid subsea waveguide has been used as the basic model to verify the accuracy of acoustic propagation model. In this paper, first of all, the finite element results of the COMSOL model are proved to be accurate by comparison, and the sound propagation of the low frequency point source under the elastic seabed is modeled and simulated. The influence of shear wave on acoustic propagation and the phenomenon of interfacial wave in the process of propagation are compared and analyzed. The actual ocean acoustic propagation environment is a three-dimensional environment with spatial variation. In this paper, the COMSOL model is extended to the three-dimensional ideal waveguide and the propagation characteristics are analyzed. In addition to the above contents, the computational efficiency and computer hardware consumption of COMSOL software in two-dimensional and three-dimensional models are compared, and the optimal application range of PML is studied. The application of the sound field model of the 3D horizontal ideal waveguide is established by using the app developer provided by the software, which provides a new idea for the commercial finite element software, which is represented by COMSOL, to better apply to the practical sound propagation problem.
【学位授予单位】：哈尔滨工程大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P733.21

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