舰船雷击瞬态电磁场时空分布特性

Time and Spatial Characteristics of Transient ElectromagneticField Distribution Generated by Lightning Stroke on Ships

针对舰船在遭受雷击时表面瞬态电磁场分布特性问题,搭建了舰船雷击瞬态电磁计算模型,计算研究了舰船不同位置注入雷电流A分量时,舰船表面电磁场分布与雷击路径、雷击电流波形以及舰船空间位置等的关系。研究结果表明:舰船表面电场强度和磁场强度波形的变化与雷击电流波形密切相关,雷击电流达到峰值时,舰船表面电场强度和磁场强度达到最大值;舰船表面的电场强度和磁场强度,在雷击点附近最大,整体上随与雷击点之间距离的增大呈指数衰减关系;雷电流泄流路径越短越宽,路径上电场强度和磁场强度衰减速率相对越快,磁场强度随距离变化的衰减速率大于电场强度。此外,曲率半径小的舰船结构,表面电磁场强度相对较大,舰船墙壁与甲板交界处电磁场强度较小,墙壁与甲板起到了电磁屏蔽作用。

A transient electromagnetic calculation model of the lightning electromagnetic field on the ship is established to study the distribution characteristics of ship surface electromagnetic fields when a ship is struck by lighting.The relationship of the distribution of ship surface electromagnetic fields with the lightning strike path,the lightning current waveform,and the ship spatial position,is calculated and studied when the lightning current component A is injected into different positions of the ship.The calculation results show that the distribution of electromagnetic field on the ship surface is closely related to the lightning current waveform of the ship struck by lightning.When the lightning current waveform reaches its peak,the electric field strength and magnetic field strength on the ship surface also reaches its maximum value.The electric field strength and magnetic field strength near the lightning strike point is the highest,and it decreases exponentially from the strike point to the surrounding area as the distance increases.The shorter(or wider)the lightning discharge path,the faster the attenuation rate of electric field strength and magnetic field strength along the path.The attenuation rate of magnetic field strength with distance is greater than that of electric field strength with distance.In addition,the electromagnetic field strength on the surface of the ship structures with small curvature radius is relatively high,and the electromagnetic field strength at the junction of the ship walls and decks is relatively low.