高空低气压下电晕放电电磁脉冲辐射特性模拟实验

为研究高空低气压下飞行器表面电晕放电电磁脉冲辐射特性,以尖端导体电晕放电为研究对象,进行了低气压下电晕放电电磁脉冲辐射特性模拟实验,给出了辐射电场幅值与气压的关系表达式,并基于气体放电和电磁场理论总结了电晕放电电磁脉冲辐射特性随电压极性、气压以及测试距离的变化规律。结果表明:电晕放电电磁脉冲辐射电场时域波形呈衰减振荡形式,持续时间约为600 ns,首脉冲方向随电压极性的不同而不同,且辐射电场分量主要集中在与放电针相同的极化方向;辐射电场频谱主要分布在500 MHz以内,在35 MHz和170 MHz处出现稳定的波峰;在气压为4~30 kPa范围内,随着气压的降低,放电电磁脉冲辐射电场增强;随着测试距离的增加,电晕放电电磁脉冲辐射电场逐渐衰减。该研究结论可为低气压下飞行器电晕放电电磁脉冲辐射特性研究提供有益参考。

Simulation experiment of electromagnetic pulse radiation of corona discharge under high-altitude low pressure

To study the electromagnetic pulse radiation of corona discharge on the surface of the aircraft under low pressure, a simulation experiment was conducted using the sharp-point conductor. The expression of radiation E-field amplitude under different pressures was achieved, meanwhile the variation of electromagnetic pulse radiation of corona discharge with voltage polarity, pressure and test distance was summed up based on the theory of gas discharge and electromagnetic field. The present work shows the following characteristics. The time-domain waveform of corona discharge radiation E-field shows damped oscillatory and the duration is about 600 ns. The direction of first pulse varies with different polarities. The radiation E-field is mainly concentrated on the polarization direction which is the same as the discharging needle. The spectrum is within 500 MHz and the peaks appear stably at 35 MHz and 170 MHz. In the range of 4 kPa to 30 kPa, the discharge electromagnetic pulse radiation E-field strengthens with the pressure decreasing, which attenuates with increasing test distance. The conclusions may provide a reference for the research of corona discharge electromagnetic pulse radiation.