负梯度声速剖面的浅海混响平均强度的垂直结构  

The vertical structure of reverberation average intensity in shallow water with downward refracting profile

作　　者：侯倩男 吴金荣[2,3] 马力[2,3] 张建兰[2,3] HOU Qiannan;WU Jinrong;MA Li;ZHANG Jianlan(University of Chinese Academy of Sciences,Beijing 100049;Institute of Acoustics,Chinese Academy of Sciences,Beijing 100190;Key Laboratory of Underwater Acoustic Environment,CAS,Beijing 100190)

机构地区：[1]中国科学院大学,北京100049 [2]中国科学院声学研究所,北京100190 [3]中国科学院水声环境挣性重点实验室,北京100190

出　　处：《声学学报》2019年第6期1036-1044,共9页Acta Acustica

基　　金：国家自然科学基金项目(11374323)资助

摘　　要：声速剖面是影响声场能量重新分配的主要参量。混响包含有双程传播和反向散射过程,文中根据全波动混响理论,从声速剖面对简正模态的垂直结构的影响出发,通过数值仿真和理论分析研究了负梯度声速剖面对双程传播损失和反向散射强度的垂直结构的影响,进而得到声速剖面对混响平均强度的垂直结构的影响。数值仿真结果表明,传播距离近的条件下,混响平均强度的垂直结构受声速剖面的影响在实际应用中可以忽略不计;传播距离足够远,并且相对声速梯度在10-4 m-1量级时,混响平均强度的垂直结构才会受声速剖面的影响有明显的变化。负声速梯度下的混响实验也表明,在有限的混响时间内,混响平均强度的垂直结构保持稳定。Sound Speed Profile(SSP)is the main factor to reallocate acoustic energy.Reverberation consists of two-way transmission and backscatteririg.Simulations and theoretical analysis had been made based on the full-wave reverberation theory,which began with the effect of SSP on the vertical structure of normal modes,to illustrate effect of SSP on the vertical structure of two-way transmission loss,as well as the vertical structure of backscattering intensity in shallow water.On this basis the Vertical Structure of Reverberation Average Intensity(VSRAI)had been analyzed.The result shows that VSRAI can be recognized as steady with SSP if the transmission range is not large enough.While the vertical stricture will have significant change when the transmission range is large enough with the relative sound speed gradient in order of 10-4 m-1.An experiment in shallow-water waveguide with downward refracting profile showed good agreement with above conclusion,which VSRAI kept steady in limited reverberation during.

关 键 词：反向散射 垂直结构 声速剖面 传播距离 平均强度 混响时间 传播损失 浅海混响 

分 类 号：P733.2[天文地球—物理海洋学]