论文标题
部分可观测时空混沌系统的无模型预测
A Spectral Method for Depth-Separated Solution of a Wavenumber Integration Model in Horizontally Stratified Fluid Acoustic Waveguides
论文作者
论文摘要
波数集成模型被认为是计算海洋声学中任意水平分层介质的最精确算法。与正常模式方法相反,它不仅考虑了离散的波数频谱,还考虑了连续频谱组件,从而消除了水平分层介质模型近似中的误差。传统上,分析方法和半分析方法已被用来求解波数集成方法中深度分离的波方程,而数值溶液通常集中在有限的差异方法和有限元方法上。在本文中,提出了使用Chebyshev- -TAU光谱法与域分解策略结合的算法,以求解深度方程,并相应地开发了一个名为WISPEC的数值程序。所提出的算法不仅可以模拟点源激发的声场,而且还可以通过无限线源激发的声场。该算法的关键思想是首先通过Chebyshev--TAU光谱法离散每个层的深度方程,然后通过结合边界和界面条件同时解决每个层的方程。设计了一些代表性的数值实验来测试WISPEC的准确性和速度。在同一配置下运行的不同软件程序结果的高度一致性证明,本文提出的数值算法是准确,可靠且数值稳定的。
The wavenumber integration model is considered to be the most accurate algorithm for arbitrary horizontally stratified media in computational ocean acoustics. In contrast to the normal mode approach, it considers not only the discrete wavenumber spectrum but also the continuous spectrum components, eliminating errors in the model approximation for horizontally stratified media. Traditionally, analytical and semianalytical methods have been used to solve the depth-separated wave equation in the wavenumber integration method, and numerical solutions have generally focused on the finite difference method and the finite element method. In this paper, an algorithm for solving the depth equation using the Chebyshev--Tau spectral method combined with a domain decomposition strategy is proposed, and a numerical program named WISpec is developed accordingly. The proposed algorithm can simulate not only the sound field excited by a point source but also the sound field excited by an infinite line source. The key idea of the algorithm is to first discretize the depth equations for each layer via the Chebyshev--Tau spectral method and then solve the equations for each layer simultaneously by incorporating boundary and interface conditions. Several representative numerical experiments are devised to test the accuracy and speed of WISpec. The high consistency of the results of different software programs running under the same configuration proves that the numerical algorithm proposed in this paper is accurate, reliable and numerically stable.