三维浅海环境下孤立子内波对低频声能流的传播影响

Influence of internal solitary waves on sound propagation in three-dimensional shallow sea

针对三维浅海环境下孤立子内波对低频声信号传播特性的影响问题,基于Oxyz坐标系下的三维浅海低频声场有限元计算方法,以声能流为研究对象,仿真分析了内波存在对低频声信号传播特性的影响规律。研究结果表明:受内波影响,在xOz平面,声能流垂直分量的传播偏转角度呈现周期性的起伏规律;随着声源深度的增加,内波对声能流偏转角度的影响深度也随之增加。对xOy平面,当声源位于温跃层以上时,随着接收深度的增加,各深度平面上声能流水平分量的偏转角越大;随着声源深度的增加,内波对各深度平面上声能流的影响逐渐减弱。

In allusion to the influence of internal solitary wave on the low-frequency sound propagation in threedimensional shallow sea,the influence rules of internal wave on the propagation characteristics of low-frequency acoustic signal are simulated and analyzed in a study of sound energy flux,which is based on the finite element method of three-dimensional low-frequency sound field in shallow sea under Oxyz coordinate system.The result shows that,under the influence of internal wave,in the xOz plane,the deflection angle of the acoustic energy flux’s vertical component follows a periodic fluctuation rule,when the acoustic source depth increasing,the influence depth of internal wave on the deflection angle also increases.In the xOy plane,when the source is above the thermo cline,the deflection angle of the acoustic energy flux’s horizontal component would be wider with the increasing of receiving depth,and the influence of internal wave on acoustic energy flux would be weakens with the increasing of source depth.