弯曲通道长度及倾斜角度对雷电电磁场影响研究

为了得到弯曲通道雷电电磁脉冲场的分布特性，将电流微源偶极子进行水平分解和垂直分解，利用偶极子法对弯曲通道产生电磁场的表达式进行了推导.在此基础上就底部回击通道长度以及上部回击通道倾斜角度对地表电磁场的影响规律进行了相关研究.研究结果表明，弯曲通道的电磁场峰值主要取决于底部放电通道的长度，在中间场和远场区底部通道越长对应的电磁场幅值越小；而倾斜角度对近场区电磁场影响极小，在中间场和远场区电磁场幅值会随着倾斜角度的增加而降低，且距离越远倾斜角度对电磁场幅值的影响越明显.

The Influence of Tortuous Channel Length and Tilt Angle on Lightning Electromagnetic Field

The equations of tortuous channel LEMP (lightning electromagnetic pulse) fields are derived by decomposing the micro dipole into the perpendicular component and the horizontal component.Then the electromagnetic fields on earth surface at different bottom discharge channel length and different upper part discharge channel tilt angle are calculated.The results show that the peak-value of LEMP mainly depends on the length of bottom discharge channel,in middle and far ranges with the increase of the bottom discharge channel length,the amplitude of corresponding electromagnetic field will be smaller.The tilt angle of upper part discharge channel has little impact on LEMP in near ranges,and the amplitude of electromagnetic field in intermediate area and far area will decrease with the increase of tilt angle.Moreover,the impact of tilt angle on electromagnetic field amplitude will be greater with the increase of the distance.