复杂混合尾流气泡场的激光探测特性研究

Study on laser detection characteristics of complex mixed wake bubble field

摘要:

在实际舰船尾流激光探测过程中,激光探测系统与目标气泡层之间会存在杂质(气泡群、悬浮粒子),导致气泡回波信号信噪比降低。为了提高实际舰船尾流探测的信噪比,采用蒙特卡洛方法,仿真模拟了不同气泡层特性遮挡的情况,通过改变遮挡气泡层的厚度、数密度来探究其对目标气泡回波特性的影响,仿真得到：当遮挡气泡层存在时,回波信号会明显降低,且降低趋势会随着遮挡气泡层厚度和数密度的增加而更为剧烈。搭建了实验室条件下的模拟舰船尾流激光探测系统,对不同气泡层特性遮挡的情况进行了验证,得到了遮挡效应会随着气泡层的厚度,数密度增大而不断变强的变化规律。对测试数据进行归一化处理,实现了仿真与实验的相互验证,可为舰船尾流激光探测工程化提供支撑。

Abstract:

In the actual laser detection process of ship wake, there will be impurities (bubble groups, suspended particles) between the laser detection system and the target bubble layer, resulting in the reduction of the signal-to-noise ratio of bubble echo signal. In order to improve the signal-to-noise ratio of the actual ship wake detection, Monte Carlo method was adopted to simulate the occlusion of different bubble layer characteristics. By changing the thickness and number density of the occlusion bubble layer, the influence of the occlusion bubble layer on the target bubble echo characteristics was explored. The simulation results were as follows: When the occlusive bubble layer exists, the echo signal will decrease obviously, and the decreasing trend will be more severe with the increase of the occlusive bubble layer thickness and number density. A simulation ship wake laser detection system was built under laboratory conditions, and the occlusion of different bubble layers was verified. It was obtained that the occlusion effect would become stronger with the increase of bubble layer thickness and number density. The normalization of test data is carried out to realize the mutual verification of simulation and experiment, which can provide support for the engineering of ship wake laser detection.