电气—几何模型在雷击风险评估中计算C_d值的应用  

Application of electric-geometric model in calculating C_d

作　　者：甘庆辉 许薇 汤强 

机构地区：[1]汕头市气象局,广东汕头515041

出　　处：《气象与环境学报》2010年第1期69-71,共3页Journal of Meteorology and Environment

摘　　要：雷击风险评估中,考虑周围物体对评估目标物直接雷击次数的影响而引入了位置因子Cd,若Cd取值不能真实反映影响程度,将导致评估结果出现较大误差。利用电气—几何模型,根据周围物体和评估目标物高度以及两者的间距,按照绕击的计算方法,计算最大绕击电流Im,进而求得大于Im雷电流概率P,位置因子Cd取值确定为(1-P)值。Considering the effect of the surrounding objects of the evaluation target on direct lightning strike frequency of evaluation target, the location factor（ Cd） was applied to the lightning strike risk evaluation. If Cd value is not true, the evaluation result will be the larger error. According to the heights of the surrounding objects and evaluation target as well as the distance of both,the maximum detour lightning current（Im） was calculated by electricgeometric model. The probability of lightning current（P）more than Im was calculated, and the value of（I-P） was determined as location factor.

关 键 词：风险评估 电气-几何模型 位置因子Cd 

分 类 号：P427.32[天文地球—大气科学及气象学]