环境因素对正极性流光-先导转化过程的影响研究  

The Effect Study of Environmental Factors on Positive Streamer-leader Translation Process

作　　者：王梦寒[1,2] 张其林 侯文豪[1,2] 杨宁[1,2] 陶玉郎[1,2] 

机构地区：[1]南京信息工程大学气象灾害预报预警与评估协同创新中心,中国气象局气溶胶与云降水重点开放实验室 [2]南京信息工程大学大气物理学院,南京210044

出　　处：《科学技术与工程》2016年第20期6-14,共9页Science Technology and Engineering

基　　金：国家重点基础研究发展项目(2014CB441405);国家自然科学基金(41275009);公益性行业(气象)科研专项(GYHY201306069)资助

摘　　要：在地闪连接过程中,正极性连接先导的始发和传播是决定建筑物是否遭受雷击的关键因素之一。但已有的正先导始发模型都是基于垂直于地面且形状规则的孤立接闪杆(避雷针),并不适用于形状各异的高大建筑物。因此,基于Gallimberti提出的流光-先导转化的热动力学模型,对已有的正先导始发模型进行了改进,并推广到任意形状的高大建筑物,分析了周围的环境因素(如温度、压强和湿度)对建筑物拐角位置处的正先导始发(或称为流光-正先导转化)过程的影响。结果表明:1)标准大气条件下,建筑物(长50 m、宽50 m、高100 m)拐角处流光-正先导转化所需要的最小电晕电荷量为0.522μC,转化时间为4.26μs,电晕电荷量越小,相应的流光-正先导转化的时间越长;2)当环境温度越低、湿度越大、压强越高时,流注茎-先导转化所需要的最小电晕电荷量越大,流注茎-先导的转化时间越短,其中,湿度的影响最大。In the Cloud-to-Ground( CG) lightning connection process,the positive polarity upward connecting leader inception and propagation is one of the key factors which determines whether a ground structure is struck by lightning downward leader. But existing inception models of positive leader are based on isolated lightning rods( lightning conductors) which are vertical to the ground and have regular shapes,also,these existing inception models of positive leader do not apply to high-rise buildings of various shapes. Therefore,on the basis of the thermodynamics model of streamer-positive leader translation by Gallimberti,the previous positive leader inception model has been improved,and the improved positive leader inception model to tall buildings of any shape was extended,at the same time,the influence of environmental factors( such as the temperature,the atmospheric pressure and the absolute humidity of air) surrounding the location of the corner of the grounded structures on the positive leader inception process( or referred to as streamer-positive leader translation process) were analyzed. The results show : 1)under standard atmospheric conditions,the minus corona charge is 0. 522 μC for the transition of streamer-positive leader from the corner of the building( length 50 m,width 50 m,height 100 m),the transition time is 4. 26 μs,when the corona charge is less,the corresponding streamer-positive leader transition time is longer; 2) the lower temperature,the larger humidity and the greater atmosphere pressure,leads to require a more the amount of minus corona charge in the streamer-positive leader transition process and a less streamer-positive leader transition time,and among of the environmental factors,there is the greatest influence of humidity.

关 键 词：高大建筑物 流光-正先导转化 热动力模型 最小电晕电荷量 转化时间 环境因素 

分 类 号：P427.3[天文地球—大气科学及气象学]