摘要
利用南海北部海域的声传播实验数据分析了跨海沟条件下的声传播特性。结果表明:由于负梯度声速剖面和海底地形的共同作用,导致声能量在开始随着海沟深度变化向更深层位置上弯曲传播,传播损失在海沟中心位置附近达到最大。在海深逐渐变浅的距离上,由于海底反射使得声能量逐渐会聚,声传播损失比单纯陆坡变到深海环境下要减小20 dB以上。当会聚效果小于扩散和海底反射等引起的损失时,声传播损失达到最小,之后随着距离增大而增大;在海沟最后一段,当海深在8 km范围内从850 m突然变浅到311 m,声场能量逐渐会聚效果再次凸显,使得声传播损失减小10 dB。利用射线理论和抛物方程近似数值分析,解释了海沟环境下的由于地形变化引起的声场会聚传播特性。
The acoustic propagation characteristics in a canyon environment were analyzed using the data from the northern South China Sea.The experimental and numerical results show that the energy begins to bend to a deeper place with the depth change of the trench and the sound Transmission Losses(TLs)reach the maximum near the center of the trench due to the combined effect of the negative gradient sound velocity profile and the seabed topography.As the sea goes shallower gradually,the energy is concentrated due to the seafloor reflection,thus the TLs reduces by over 20 dB compared with the TLs results in the simple slope to the deep sea environment.What’s more,when the convergence effect is less than the combination of the loss caused by diffusion and seafloor reflection,TLs are minimized and then increase with range.In the last segment,the gradual convergence of the energy is again highlighted,and the TLs decrease 10 dB when the sea depth suddenly changes from 850 m to 311 m in 8 km.Finally,the ray theory and the parabolic equation methods are used to explain the convergence effect of sound field in a canyon environment.
作者
张青青
李整林
秦继兴
李文
吴双林
ZHANG Qingqing;LI Zhenglin;QIN Jixing;LI Wen;WU Shuanglin(State Key Laboratory of Acoustics,Institute of Acoustics,Chinese Academy of Sciences,Beijing 100190;University of Chinese Academy of Sciences,Beijing 100049)
出处
《声学学报》
EI
CSCD
北大核心
2020年第4期458-465,共8页
Acta Acustica
基金
国家自然科学基金项目(11434012,41561144006,11874061)资助。
