水平变化波导中的全局矩阵耦合简正波方法

提出了一种新的水平变化波导中声场的耦合简正波求解方法,该方法能够处理二维点源和线源问题,提供声场的双向解。该方法利用全局矩阵(DGM)一次性求解耦合模式的系数,消除了传播矩阵递推求解中存在的误差累积问题;此外,改善了现有模型中对距离函数的归一化方法,从而避免了泄露模式指数增长导致的数值溢出问题。本文还给出了绝对软海底理想波导中耦合矩阵的闭合表达式,并分析了单个阶梯下简正波耦合现象。此外,本文还计算了理想楔形波导中的声传播问题(ASA标准问题),并与解析解及COUPLE07计算结果进行了比较,结果表明该方法是一种稳定、精确的水平变化波导中的声场计算方法。

A coupled-mode method based on direct global matrix approach in range-dependent waveguides

A coupled-mode formulation for acoustic propagation in range-dependent waveguides is presented in this paper.This method is capable of providing two-way solutions to two-dimensional problems with either a point source in cylindrical geometry or a line source in plane geometry.The direct global matrix(DGM) approach is adopted in computing the coupled-mode coefficients in each segment,in order to eliminate accumulative errors in the traditional propagator matrix approach.In addition,appropriate normalized range solutions are introduced to avoid numerical overflow problems.Furthermore,closed-form expressions for coupling matrices are derived for ideal waveguides.Mode coupling in a waveguide involving a single stair step is analyzed.Numerical results for an ASA benchmark problem are also provided,which shows great agreement between the numerical solutions by this method and the analytical solutions.The numerical results indicate that the present method is numerically stable and accurate,and thus suitable for range-dependent problems.