通过利用标准简正波程序KRAKEN计算本地简正波解及耦合矩阵,进一步发展了求解水平变化波导中声场的全局矩阵耦合简正波方法(Luoetal.,"A numerically stable coupled-mode formulation for acoustic propagation in range-dependent waveguides,"Sci.China-Phys.Mech.Astron.55,572(2012)),使得该方法可以处理具有可穿透海底及随深度变化声速剖面等实际问题,并提供声场的完全双向解.本文还给出了双层波导中耦合矩阵的解析表达式,并利用其验证了本方法中耦合矩阵数值算法的精度.最后,利用改善后的全局矩阵耦合简正波模型(DGMCM)计算了美国声学学会(ASA)提出的可穿透楔形波导标准问题,将所得数值解与参考解比较,结果表明DGMCM方法可以精确处理水平变化波导中声传播实际问题.
The coupled-mode method based on the direct global matrix (DGMCM) approach for sound propagation in range-dependent waveguides [Luo et al., "A numerically stable coupled-mode formulation for acoustic propagation in range-dependent waveguides," Sci. China-Phys. Mech. Astron. 55, 572 (2012)] is further developed. The normal mode model KRAKEN is adopted to provide local modal solutions and their associated coupling matrices. As a result, the model DGMCM is capable of providing full two-way solutions for the two-dimensional realistic problems characterized by a penetrable bottom and a depth-varying sound speed profile. In addition, the closed-form expressions of coupling matrices for sound propagation in a range-dependent, two-layer waveguide are proposed. The numerical solutions of the coupling matrices by DGMCM agree well with the analytical solutions. Sound propagation in a penetrable wedge is solved by the updated DGMCM model. The numerical results indicate that the updated DGMCM model is numerically stable and accurate, and can provide benchmark solutions for realistic range-dependent problems.