基于时域有限差分法舰载活动设备电磁场分析

Electromagnetic field analysis of shipborne moving equipments based on FDTD method

舰载活动设备产生的电磁干扰因无法采用传统的舰船消磁技术消除而需准确评估。以舰载火炮为例，采用时域有限差分法分析了舰载火炮在姿态改变时的电磁场特性变化。为提高建模精度，引入平均电参数对金属设备进行建模。通过坐标变换，提出了修正的差分方程对金属设备与Yee网格不重合的边缘部分进行模型修正。通过算例对比验证了算法的有效性。仿真结果表明：舰载火炮在姿态改变时电场有0．6～3．8V／m的变化，磁场有0．0016～0．01A／m的变化，这类电磁场变化对舰船电磁兼容性的影响不容忽视。

The electromagnetic interference of shipborne moving equipments snouia be evaluated correctly, because it cannot be degaussed by traditional methods. Taken artilllery as an example, the finite difference time domain（FDTD） method was applied to analyze the changes of electromagnetic fields of the artillery with the gesture changing. The average electrical parameters were adopted to improve the model accuracy of metal equipments. By changing coordinates, the modified differ- ence equations were proposed to modify the metal edges, which cannot match the Yee grids. The algorithm was proved effectively by example comparisons. At last, results indicated that the changes of electric fields are 0. 6 - 3. 8 V/m, and the changes of magnetic fields are 0. 0016-0.01 A/m when the gesture of the artillery changes. The influences of these kinds of electromagnetic changes to ship electromagnetic compatibility cannot be ignored.