浅海波浪与内波对声传播的影响
文献类型：学位论文
| 作者 | 王先华 |
| 学位类别 | 博士 |
| 答辩日期 | 2007-06-08 |
| 授予单位 | 中国科学院声学研究所 |
| 授予地点 | 声学研究所 |
| 关键词 | 线性内波 孤立子内波 起伏 闪烁指数 简正波耦合 |
| 其他题名 | The Influence of Shallow Water Surface Wave Fluctuation and Internal Waves on Sound Propagation |
| 学位专业 | 声学 |
| 中文摘要 | 本文研究包括两部分。第一部分研究海面波浪起伏对声传播的影响；第二部分研究线性内波和孤立子内波引起的声速起伏对声场的影响。 针对2004年和2005年在南海某海域同一传播路径上两次声传播实验结果差异，分析发现实验结果的差异主要是由于波浪起伏引起的。当考虑海面波浪起伏的影响后，利用实验测量的声传播损失曲线可以较好地反演海底吸收系数。本项研究表明浅海海面波浪起伏对声传播的影响很大，因此在进行水下声传播规律的研究或地声参数反演研究时，应当充分考虑海面波浪起伏的影响。 根据1996年黄海实验测量的海洋水文数据建立的内波模型，数值模拟研究了声源分别位于温跃层以上和温跃层以下时内波引起的声速起伏对声场的影响，并考察了各号简正波在内波存在时的耦合情况。数值模拟结果表明，线性内波和非线性内波引起声速起伏，导致简正波的耦合，使得能量重新分布，从而引起声场起伏。对于声源在跃层以上的情形，在初始距离低号简正波起伏较小，简正波闪烁指数较小，随着距离增加各号简正波起伏都较大，简正波闪烁指数较大。声源在跃层以下时，低号简正波起伏较小，高号简正波起伏较大，在跃层以上区域声场起伏较大，声场闪烁指数较大，而跃层以下区域声场起伏较小，声场闪烁较小。 |
| 英文摘要 | The influence of shallow water surface wave fluctuation and internal waves on sound propagation is studied in this paper. Firstly, the influence of surface wave fluctuation on sound propagation is studied. Great difference has been observed between two transmission loss (TL) curves measured during two experiments conducted in the same routine in South China Sea (SCS) in 2004 and 2005 respectively. It is shown that the difference between the two TL curves accounts for the different surface wave fluctuations. It is also shown that the measured TL curve is practicable for the sea bottom attenuations estimation, if the effect of the surface wave fluctuation were compensated. In one word, the surface wave fluctuation should be taken into consideration when the research on sound propagation (including geoacoustic inversion) is conducted duo to its great influence. Secondly, the influence of sound-speed fluctuations induced by internal waves, including linear internal waves and nonlinear internal solitary waves, on the fluctuations of sound field is studied by using numerical simulations. The internal wave is modeled on the basis of environment measurements conducted during a Yellow Sea experiment in 1996. The source localized below and above the thermocline is taken into consideration. The normal mode coupling caused by the internal waves is also studied. It is shown that the redistribution of energy between coupling normal modes is caused by the sound-speed fluctuation induced by linear internal wave and nonlinear internal wave, which causes the fluctuations of sound field. In the case of source being above the thermocline, lower modes have weak fluctuation and its scintillation index is weak in near distance. For further distance, fluctuations of all normal modes and its scintillation index become stronger. In the case of source being below the thermocline, the fluctuations of lower modes are weak, and the fluctuations for higher modes are stronger. |
| 语种 | 中文 |
| 公开日期 | 2011-05-07 |
| 页码 | 73 |
| 源URL | [http://159.226.59.140/handle/311008/186]  |
| 专题 | 声学研究所_声学所博硕士学位论文_1981-2009博硕士学位论文 |
| 推荐引用方式 GB/T 7714 | 王先华. 浅海波浪与内波对声传播的影响[D]. 声学研究所. 中国科学院声学研究所. 2007. |
入库方式： OAI收割
来源：声学研究所
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