针对北极部分海域中的双声道波导现象,研究了冰层覆盖下水平变化双声道波导中的声传播。使用微扰法推导并确定了粗糙下表面的冰层反射系数,结合Bellhop射线模型,计算并分析了实测海域中双声道波导水平变化时的声传播特性,并研究了声源深度、声源入射角以及声源频率对水平变化的双声道波导中声传播的影响规律。结果表明,在北极,深海声道中的声传播大多被限制在深海声道的上、下边缘之间;声源与水平变化的深海声道轴处于同一深度时声传播损失较小,当声源位于深海声道边界以外时,水平变化的声速剖面相比于水平不变时具有更低的声传播损失;入射角对双声道波导中声传播影响较小;随着声源频率的增加,表面声道中声传播损失也随之增大,但是对深海声道影响不明显,在相同频率下水平变化的声速剖面更利于声传播。

Acoustic propagation in horizontally varying double duct waveguides under ice cover was investigated for the phenomenon of double duct waveguides in some Arctic seas. The ice reflection coefficients on the rough undersurface were derived and determined by the perturbation method, and the acoustic propagation characteristics of the horizontally varying double duct waveguide in the measured sea area were computed and analyzed by combining with the Bellhop ray model, and the influences of the depth of the sound source, the angle of incidence of the sound source and the frequency of the sound source on the acoustic propagation in the horizontally varying double duct waveguide were also investigated. The results show that in the Arctic, acoustic propagation in the deep-sea sound duct is mostly confined to the upper and lower edges of the deep-sea sound duct; the acoustic propagation loss is smaller when the sound source is at the same depth as the horizontally varying deep-sea sound duct axis, and the horizontally varying sound velocity profile has a lower acoustic propagation loss compared to the horizontally unchanged one when the sound source is located outside of the boundary of the deep-sea sound duct; the angle of incidence has a smaller effect on the acoustic propagation in the double duct waveguide; as the frequency of the sound source increases, the acoustic propagation loss in the surface duct increases, but the effect on the deep-sea duct is not obvious, and the horizontally varying sound velocity profile is more favorable for acoustic propagation at the same frequency.