浅海中船舶尾流产生的感应电磁场

Study of the electric field induced by the wake of a moving ship

为了完善船舶电磁场的特性研究,为船舶水下远程探测和特征信号控制提供参考,利用电磁场边界条件求解麦克斯韦方程组,得到了浅海中船舶尾流感应电磁场的数学模型,并对船舶尾流感应电磁场的特性进行了仿真分析。重点分析了尾流感应电磁场的水下特性,结果显示感应电磁场信号在水下具有良好的特性:长波长、低频率,持续时间长,距离越远幅值衰减速度越小,功率谱为线谱,可用于船舶的远程水下探测。海上实测船舶尾流感应电场数据与理论仿真对比表明,实测数据的量级、变化趋势和功率谱均与理论模型的计算结果一致,证明了理论模型的正确性。

In order to improve the research of the features of electromagnetic fields of a ship and provide a reference for the remote detection and the control of underwater feature signals of the ship, a mathematical model representing induced electromagnetic fields associated with ship wakes was built by solving MaxwelFs equations in finite depth seas. The simulation and analysis were conducted on the features of the electromagnetic field induced by ship wakes. The analysis was focused on the underwater sea features of the ship wake induced electromagnetic field. The results show that the induced electromagnetic field signals have significant under-water sea features including long wavelengths, low frequency, long duration, line spectrum, and that the longer the distance, the smaller the amplitude decay rate. All these features are significant for the remote under-water sea detection of a ship. Comparative study of the real electric field signals and the theoretical simulation data reveals that they are consistent in order of magnitude, trend and power spectrum, which demonstrates the correctness of the proposed model.