Lightning return stroke current radiation in presence of a conducting ground: 1. Theory and numerical evaluation of the electromagnetic fields
Lightning return stroke current radiation in presence of a conducting ground: 1. Theory and numerical evaluation of the electromagnetic fields
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DOI：
10.1029/2007jd008553
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发表时间：
2008-03
影响因子：
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通讯作者：
F. Delfino;R. Procopio;M. Rossi
中科院分区：
文献类型：
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作者：
F. Delfino;R. Procopio;M. Rossi
[1]本文提出了描述雷击导体地面辐射电磁场的一般理论。推导的绿色函数解决这个问题所必需的详细讨论，并确定的电磁场分量的表达式进行的形式，最大限度地减少了最终的计算成本。然后提出了一种电磁场的数值计算方法，它表明，它可以用于从任何“工程模型”表示的雷电流分布沿着通道。这种方法是基于一个新的有效的评估出现在电磁场表达式中的所谓索末菲积分，而不诉诸于任何形式的近似公式。数值处理的索末菲积分的特点是适当的细分的集成域，使用的Romberg技术和确定一个合适的上限的错误，由于积分截断。在这项工作的第二部分，它将显示如何开发的理论提供的结果可以用来评估的有效性，最常见的简化方法计算的雷电辐射在一个有损耗的接地平面。
[1] The general theory describing the electromagnetic field radiated by a lightning stroke over a conducting ground is presented in this paper. The derivation of the Green functions necessary to solve the problem is discussed in detail, and the determination of the expressions for the electromagnetic field components is carried out in a form that minimizes the final computational costs. A method for the numerical evaluation of the electromagnetic field is then proposed, and it is shown that it can be used starting from any “engineering model” representation for the lightning current distribution along the channel. Such method is based on a new efficient evaluation of the so-called Sommerfeld's integrals appearing in the electromagnetic field expressions, without resorting to any kind of approximated formulas for them. The numerical treatment of the Sommerfeld's integrals is characterized by a proper subdivision of the integration domain, the use of the Romberg technique and the determination of a suitable upper bound for the error due to the integral truncation. In the second part of this work it will be shown how the results provided by the developed theory can be used in order to assess the validity of the most common simplified approach for the calculation of the lightning radiation over a lossy ground plane.