界面混响的耦合简正波理论研究

利用耦合简正波理论分析了粗糙界面散射引起的混响。引入了粗糙海底以及海面引起的各个模态间的耦合系数表述粗糙界面对声场的散射过程。结合风浪谱Pierson模型,仿真了不同海况下的海面混响,重点在于分析不同海况下海面起伏对海底混响的影响。利用耦合系数的求解从粗糙海面引起模态间能量耦合的角度对这种影响进行了机理性的探究。结果表明,尽管在浅海中海底混响占支配性地位,但随着海况等级的增加,海面散射对海底混响是有影响的,而这种影响可以从粗糙界面对声波模态间的耦合进行机理分析。 

Research of surface reverberation using coupled mode theory

Reverberation caused by rough surface scattering is investigated using the coupled mode theory.Firstly, coupled coefficients that describe the scattering caused by irregular bottom or rough sea surface are derived based on coupled mode theory.Then the decaying rules of surface reverberation level are simulated in different sea states, which are realized according to Pierson spectrum,and the surface effect on the bottom reverberation is also discussed. The emphasis of this paper is to demonstrate the mechanism of rough surface scattering by describing the transfer of energy between different modes.It is indicated that bottom reverberation,which is dominated among other kinds of reverberation in shallow water,is effected by the sea surface scattering as the sea state level increases.