Measurement of the rear‐face temperature of metals struck by lightning long‐duration currents
Measurement of the rear‐face temperature of metals struck by lightning long‐duration currents
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DOI：
10.1002/etep.16
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发表时间：
2004-07
影响因子：
--
通讯作者：
I. Metwally;F. Heidler;W. Zischank
中科院分区：
文献类型：
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作者：
I. Metwally;F. Heidler;W. Zischank
本文对不同金属在雷电长持续电流作用下的后端面温升进行了实验研究。实验研究模拟了可能击中飞行中或着陆的飞机和火箭的自然闪电的一个电流分量的热效应；军需品和核武器；以及石油/天然气工业的储罐/收集罐和管道。在雷击的情况下，后表面的温升必须小于一定的限制，以避免灾难性的破坏/事故。一个复杂的高速红外摄像机，图像频率为50 Hz，温度范围高达1200°C，用于测量后脸温度曲线作为坐标和时间的函数。根据电弧运动的光学观察、光斑直径的物理测量以及阴极和阳极光斑能量平衡的研究，对结果进行了解释。结果表明，对于恒定电荷转移，具有较高振幅的闪电长持续电流会导致较高的后表面温升，从而导致较高的事故风险。后端面最大磁芯温度和前端面光斑直径均随平均电流幅值呈指数增长。最大后端面堆芯温度随电荷呈指数变化，随作用积分呈线性变化。测试电极正极性的电流注入使除铝外的所有金属的后表面温度较低，其趋势相反。版权所有©2004 John Wiley & Sons， Ltd
This paper presents an experimental investigation of the rear-face temperature rise of different metals struck by lightning long-duration currents on the front face. The experimental investigation simulates the heating effect of one current component of the natural lightning flashes that may strike in-flight or landed aircraft and rockets; munitions and nuclear weapons; and storage/collection tanks and pipelines of the petroleum/gas industries. In the case of a lightning strike the rear-face temperature rise must be less than certain limits to avoid catastrophic damage/accidents. A sophisticated high-speed infrared camera, having an image frequency of 50 Hz and a temperature range up to 1200°C, is used to measure the rear-face temperature profiles as a function of the coordinates and time. The results are interpreted in light of the optical observation of the arc motion, physical measurement of the spot diameter, and study of the energy balance at the cathode and anode spots. The results reveal that for constant charge transfer, lightning long-duration currents having higher amplitudes give a higher rear-face temperature rise and hence a higher risk of accidents. Both the maximum rear-face core temperature and the front-face spot diameter exponentially increase with the mean current amplitude. Moreover, the maximum rear-face core temperature varies exponentially with the charge and linearly with the action integral. Current injection with positive polarity of the test electrode gives a lower rear-face temperature for all metals used except for aluminium where the trend is reversed. Copyright © 2004 John Wiley & Sons, Ltd.