基于有限差分法的高层建筑物雷电连接过程模拟研究

Simulation research on lightning connection process of high building based on finite difference method

为研究雷电与高层建筑物的相互作用,该文构建了一个雷电连接过程有限差分计算模型。运用Matlab编写程序,设置网格大小,确定吸收边界,引入松弛因子,对离散化后的线性方程组进行求解,计算得到空间分布的电势值,实现对闪电通道底部二维电场的数值模拟,研究建筑物高度、闪电先导起始位置对高层建筑物雷电连接过程的影响,模拟得到闪电路径图和电势等高线分布图,并将模拟得到的结果与实例进行了比对。结果表明,所构建的模型能很好地模拟出下行先导主通道向下发展特征,突出的下垫面因素会对雷电电场传播产生影响,高层建筑物对雷电存在一定的“吸引”作用,要加强高层建筑物及空旷场地孤立建筑物的雷电防护能力,防范于未然,降低雷灾风险。

In order to study the interaction between lightning and high building, a calculation model of lightning connection process was constructed based on finite difference method. Programming in Matlab was conducted to set the grid size, determine the absorption boundary and introduce a relaxation factor. Then, by solving the discrete linear equations, the potential value of the spatial distribution was calculated. The numerical simulation of the two-dimensional electric field at the bottom of the lightning channel was realized. The simulation results show the lightning path map and the potential contour map could be used to study the influence of building height and lightning pilot location on the lightning connection process of high building. The results of the simulation were compared with the real cases. The results show that the model constructed in this paper could well simulate the downward development characteristics of the main channel of the downlink pilot. The protruding surface factors would influence the propagation of lightning electric field and high building would “attract” lightning. It is necessary to improve lightning protection ability of high buildings and isolated buildings, to nip in the bud and reduce the risk of lightning disaster.