波浪起伏对噪声场空间特性的影响

摘要

风成噪声是海洋环境噪声的重要组成部分,现有的噪声预报模型基本都是基于海面为绝对软平坦边界的假设建立的,然而海面波浪起伏引起的散射必然造成声波能量的衰减,改变声场的空间分布.本文通过引进P-M波浪谱模型来描述海面粗糙度,利用小斜率近似求解二维粗糙海面下相干反射系数,然后将海面相干反射系数引入到声传播模型中,使得模型能够考虑界面粗糙对噪声传播的影响,基于简正波理论建立了粗糙界面下噪声场空间特性预报模型.仿真分析了海面粗糙度对噪声场空间特性的影响.结果表明:海面起伏会引起噪声强度的衰减,并影响空间相关函数的幅度,还会改变噪声场的水平相关半径.%Wind-generated noise is an important component of oceanic noise.Existing noise prediction models were established based on the assumption that sea surface is an absolutely soft and flat boundary.However, scattering caused by fluctuant sea surface attenuates acoustic wave energy, resulting in changes in the spatial distribution of the sound field.This paper describes the roughness of the sea surface by introducing the PM wave spectrum model.The coherent surface reflection coefficient for 2-D rough surfaces was solved using a small slope, and the coherent surface reflection coefficient of the sea surface was introduced into the acoustic propagation model.The model could consider the effect of the roughness of the sea surface on the spatial characteristics of noise field.Normal wave theory was used to establish a prediction model on the spatial characteristics of noise field at the coarse interface.The simulation analyzed the effect of sea surface roughness on the spatial characteristics of noise field.Results show that sea fluctuation will lead to decay of noise intensity, affect the amplitude of the spatial relevant function, and change the horizontal relevant radius.