高建筑对周围建筑雷击保护距离的模拟

在已有先导连接参数化方案的基础上，选取近地面层为研究区域，保持方案中其他基本参量不变，通过改变闪电的空间形态，在同一建筑分布的背景下进行多次闪电模拟。研究多个建筑之间的屏蔽作用以及建筑雷击保护距离与建筑相关特征参数之间的关系，结果表明:高建筑对矮建筑具有屏蔽作用，并存在一个临界保护距离，当高、矮建筑高度分别为190 m和165 m，宽度均为20 m时，建筑之间的距离在12 m以内，矮建筑受高建筑完全保护不遭受雷击；建筑之间的距离超过12 m，矮建筑遭雷击次数明显增多。

Simulation on the Stroke Protection Distance of Tall Buildings to Surrounding Buildings

Lightning is a kind of strong discharge phenomena in the atmosphere. It has a great impact on human living space especially cloud to ground lightning, making it widely concerned. Through a large number of lightning observation, the tip and the corner of tall buildings are usually striken rather than the relative low buildings and ground. The tall building can make surrounding atmospheric electric field produce a strong distortion effect, so that the tip and the corner of tall buildings trigger upward leader easier, connected with the downward leader. Numerous studies on single building attachment process are carried out, while in real urban environment, buildings are not isolated, and therefore, shielding effects between multiple buildings and the relationship between stroke protection distance of building and the related characteristic parameters of buildings are discussed. On the basis of the existing parameterization scheme of leader attachment process, a region near the ground is selected as study area, by changing spatial forms of lightning while keeping the other basic parameters constant. A series of lightning simulation experiment is conducted in the context of distribution of the same buildings. Results show that under the distribution of multiple buildings, the tall building is more intense in the environmental electric field distortion than the low building, upward leader is easier to be triggered. Meanwhile, the tall building has a shielding effect to the low building, and has a critical value of protection distance of the effect of low building, when the distance between tall building and low building is under the critical, the low building is safe from stroke, otherwise, the rate of low building being stroke has a upward trend. In addition, the result comes out that the critical value of protection distance and the height of tall building is positively correlated, and the height of low building is negatively correlated. Finally, the relationship between the critical value of protection distance and the building height is fitted, providing a reference value for lightning protection designing work.