南海北部海域内波环境下声传播损失起伏统计特性

浅海内波会引起声传播能量随时间的起伏变化,进而影响水声设备的工作性能.本文利用2015年南海北部一次浅海声场起伏实验数据,对比分析了浅海线性内波和孤立子内波条件下的声传播损失统计特性.在孤立子内波条件下,声传播损失起伏明显加剧,可达11 dB,且分布明显展宽,相对于线性内波的环境,声传播损失起伏可增加5 dB.从简正波...

Statistics of sound transmission loss fluctuation due to internal waves in the north of the South China Sea

The performance of ocean acoustic devices is under the influence of sound fluctuation due to internal waves in shallow water.In order to study the intensity fluctuation of sound propagation due to internal waves,an experiment was conducted in 2015 in the northern of the South China Sea,with both linear internal waves and internal solitons existed.The statistics on transmission loss from a bottom anchored transducer to a vertical line array is made to analyze the evident variety due to linear internal wave and internal solitons.The fluctuation of transmission loss due to internal solitons can reach to 11 dB which is 5 dB greater than the fluctuations due to linear internal waves.And the probability distribution of the transmission loss due to internal solitons is much wider than that due to linear internal waves.In terms of normal mode,there is obvious coupling phenomenon among normal mods due to internal waves and the intensity fluctuation of the 3 rd mode up to 20 dB is observed in this experiment.The energy fluctuations of the normal modes due to linear internal waves and internal solitons are analyzed to explain the physical mechanism of sound intensity fluctuations.