空气声源激发的浅海声场的理论研究

The theoretical study of acoustic field in shallow water excited by an aero source

研究了将空气中声速分布建模为Epstein分布,水层和海底均为均匀分布的三层介质模型的条件下,空气中点源激发的水下声场。既推导得到了声压场的形式解,通过数值分析,表明空气中点源激发浅水波导,在水层中形成的波导简正波具有实数本征值,可以远距离传播,称其为"水波"。空气层中的Epstein波导简正波在水层中为非均匀波,传播速度取决于空气中声速,称其为"水面波",并指出空气中声源运动产生的水面波多普勒频移大于水波多普勒频移。

The underwater acoustic field excited by an aero-source is studied when the air sound velocity is assumed as Epstein distribution, and the shallow water and the seabed are assumed as iso-speed layers(Epstein model). Acoustic pressure solution is obtained. The numerical analysis results indicate that normal modes with true eigenvalues exist when the shallow water column is excited by an aero-source and they can propagate over long distance. The normal mode is named "water wave" in this paper. The normal modes existing in the aero Epstein waveguide are lateral waves while traveling in the water layer with the sound speed of the air. And the lateral wave is named as "surface water wave", on which the Doppler shift caused by the aero moving source is greater than that on the "water wave".