矢量拖线阵水听器流噪声响应特性

针对传统拖线阵流噪声理论的局限性, 建立了完善的矢量拖线阵流噪声理论分析方法, 可全面准确地揭示矢量拖线阵流噪声响应特性. 基于细长圆柱的湍流边界层压力起伏Carpenter模型, 采用波数-频率谱分析方法对矢量拖线阵流噪声响应特性进行了理论研究, 导出了圆柱形矢量水听器流噪声响应的声压和振速自功率谱及其互功率谱的解析表达式, 定量分析了流噪声响应功率谱与拖曳速度、水听器尺寸、套管尺寸和材料等参数之间变化规律; 另外, 还讨论了圆柱形矢量水听器偏离护套轴线时矢量拖线阵流噪声响应, 导出了流噪声响应的声压、径向和轴向振速自功率谱及其互功率谱的解析表达式, 数值计算结果表明: 轴线偏移距离对声压和轴向振速的高频噪声的影响要大于对低频噪声的影响, 而对径向振速的全频段噪声都有明显影响, 且对振速分量影响要远大于对声压影响.

Flow-induced noise calculations for vector hydrophones in towed arrays

The purpose of this study is to develop an integrated analytical method of flow-induced noise for vector hydrophones in towed arrays and discuss the parameters that influence flow-induced noise character. Based on Carpenter turbulent boundary layer pressure fluctuation model for slender cylinder, the power spectra and cross power spectra of acoustic pressure and particle velocity of flow-induced noise, are deduced by utilizing the wavenumber-frequency spectral analysis. It is shown that the flow-induced noise is determined by the towed speed, the size of both vector hydrophones and elastomer tube, the material parameters of elastomer tube and so on. In addition, the condition that cylindrical vector hydrophones are distributed non-axially in elastomer tube is also taken into account. Considering the influence of the axis-off distance on acoustic pressure, axial particle velocity and radial particle velocity, a set of numerical results show that the influence of the axis-off distance on the high-frequency component of the acoustic pressure and axial particle velocity is greater than that on the low-frequency component. The radial particle velocity is influenced by the axis-off distance within the full frequency range. The impact of the axis-off distance on the particle velocity is far greater than that on acoustic pressure.