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题名	空气中声源激发水下声场的理论与实验研究
作者	李辉
学位类别	博士
答辩日期	2008-05-29
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	空气声源 水下声场 简正波 多普勒频移 实验研究
其他题名	Theoretical and experimental studies on the sound field by an airborne source
学位专业	声学
中文摘要	空气中声源激发水下声场问题是实现水下探测空中目标的物理基础，有着重要的应用背景和实际需求。但是空气中声波入射海面时，由于空气-海水两种介质阻抗相差很大，大部分能量被海面反射，能够入射水中的能量相对很少，为进行空气中声源激发水下声场问题研究带来了一定的困难。基于此本文对空气中声源激发水下声场的理论和实验进行了研究。 理论上，采用Henrik建立水下移动声源简正波模型的方法，将Chapman的空气中静止声源激发水下声场的简正波模型推广至运动声源，提出了空气中移动声源激发水下声场的频域简正波表达式。利用该表达式对目前比较流行的简正波程序Kraken进行了改进，并通过与波数积分模型OAST的计算结果进行比较，验证了该表达式的正确性。 利用本文所提空气中运动声源激发水下声场的简正波表达式，研究了有限带宽的声源信号作用下，声源和接收的运动对声场的影响。利用该表达式，本文研究了声源的高度对声场的影响。 本文还介绍了空气中声源激发水下声场的三次实验及相关的实验数据处理结果。对实验数据的处理结果包括：音箱声源声源级的测量；声源下方附近水下声强随深度的变化规律研究；空中声源高度和水平距离的估计；1000m以内的传播损失变化规律研究等。
英文摘要	Since the acoustic impedance of the air is much lower than the impedance of the water, the reflected wave dominates the energy for an acoustic wave incident from air to water, and the transmitted wave is usually negligible. Therefore, both the theoretical and the experimental researches on underwater sound field excited by an airborne source are relatively less than that by a source in water. In this paper, the theoretical and experimental studies have been conducted. Theoretically, on the basis of Henrik’s spectral and modal representations and the Chapman’s normal mode theory, a normal modal representation for the acoustic pressure field in the stratified waveguides by a horizontally moving airborne source is presented. In principle, the normal mode representation could be easily implemented in many underwater acoustic normal-mode codes. As an example, it has been implemented in Kraken, a classic normal mode code. The numerical results are shown to be in accordance with those by OAST, a wave-number integration code. The presented the normal mode expression is also used to study the influences of the source and receiver motions on the sound field. The differences of sound field duo to the different heights of the airborne source are also studied. Three experiments on the subject of sound field by an airborne source have been conducted by the National Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, and will be introduced in this paper. The data processing results are also presented in this paper, which include: the source level calibration of a sound box; the energy distributing versus depth below and near the source; the estimation of source location (height and range); the transmission loss within range up to 1000m.
语种	中文
公开日期	2011-05-07
页码	93
内容类型	学位论文
源URL	[http://159.226.59.140/handle/311008/280]
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	李辉. 空气中声源激发水下声场的理论与实验研究[D]. 声学研究所. 中国科学院声学研究所. 2008.

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