水下尾流相干探测的理论与实验研究

Theoretical and Experimental Study of Underwater Ship Wakes Based on Coherent Detection

研究水下舰船尾流形成初期相干光探测干涉图像的特性及不同水体条件下干涉图像的变化情况,仿真不同退偏情况下的干涉图像。基于Monte Carlo方法建立了气泡群散射的仿真模型,分析气泡群多重散射的强度特性并模拟前向及后向接收屏的光强分布情况。搭建马赫-曾德尔干涉光路进行水下舰船尾流气泡的相干探测实验,验证了理论和模拟的准确性。结果表明,设计的光路可以测量该实验条件下尾流前向散射光的干涉图,不同水环境下干涉图的光强和对比度具有很大的差异,可以通过对干涉图的直接处理来进行水环境的区分。利用干涉法进行尾流区域判断,为尾流区域的探测提供了一个新的思路。

The characteristics of underwater ship wake bubbles and interference images under different water conditions by laser with high degree of coherence are studied, and the coherent figures with different depolarization angles are simulated. The simulation model of laser scattering detection by ship wake bubble clusters is based on Monte Carlo method. By the simulation, the intensity of multiple scattering is studied and the distributions of intensity received by forward and backward screens are also given. The Mach-Zehnder experimental platform is set up to detect underwater ship wake bubbles with coherent method in order to verify the veracity of theory and simulation. The results show that it is available to acquire useful forward-scattering information through coherent images. There are great differences among different water conditional coherent images which can be used to distinguish different kinds of water conditions, and further, different sorts of ship wakes. The research offers a new method to judge ship wakes and provides a new idea about ship wake zone detection.