有限平面障板对低频指向性的影响

Influence of finite-sized baffle on low frequency directivity

为提高对水下目标的远程探测能力,降低水下航行体系统工作频率不失为一种较易实现的好方法。矢量传感器在各向同性噪声场中可以获得较大的低频检测增益,且其低频指向性好、体积小、重量轻,但是将矢量传感器安装在水下航行体头部的导流罩内时,传感器的后障板对其指向性有影响,从而影响水下航行体对目标定向的能力。该文从声学原理出发,对平面波在有限平面障板边界上的声压场和振速场进行了理论分析,在此基础上建立了矢量传感器在有限平面障板下的指向性模型,并通过计算机仿真分析,研究了有限障板对低频指向性的影响。设计了实验室试验系统,并进行了试验验证。试验结果表明,仿真分析与水池试验结果一致,证明了该模型的正确性,为减小有限障板对矢量传感器性能的影响奠定了基础。

Underwater vehicles usually work at higher frequencies in a passive acoustic target detection mode,which has a narrow detection range.In order to expand the range,acoustic vector sensors,which work at low frequencies,can be used.When using vector sensors,their directivity is influenced greatly by baffle plates with the limited dimension.Reducing the influence of the baffle plates is an important issue.In this paper,the directivity model of a vector sensor with finite-sized baffle plates is presented theoreti-cally.Comparison between computer simulation and the tank measurements show the validity of the desc-ribed directivity model.