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Title: A stepped leader model for lightning including charge distribution in branched channels

The stepped leader process in negative cloud-to-ground lightning plays a vital role in lightning protection analysis. As lightning discharge usually presents significant branched or tortuous channels, the charge distribution along the branched channels and the stochastic feature of stepped leader propagation were investigated in this paper. The charge density along the leader channel and the charge in the leader tip for each lightning branch were approximated by introducing branch correlation coefficients. In combination with geometric characteristics of natural lightning discharge, a stochastic stepped leader propagation model was presented based on the fractal theory. By comparing simulation results with the statistics of natural lightning discharges, it was found that the fractal dimension of lightning trajectory in simulation was in the range of that observed in nature and the calculation results of electric field at ground level were in good agreement with the measurements of a negative flash, which shows the validity of this proposed model. Furthermore, a new equation to estimate the lightning striking distance to flat ground was suggested based on the present model. The striking distance obtained by this new equation is smaller than the value estimated by previous equations, which indicates that the traditional equations may somewhat overestimatemore » the attractive effect of the ground.« less
Authors:
;  [1] ;  [2] ;  [3]
  1. School of Electrical Engineering, Shandong University, Jinan 250061 (China)
  2. Beijing Key Lab of HV and EMC, North China Electric Power University, Beijing 102206 (China)
  3. (China)
Publication Date:
OSTI Identifier:
22305929
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 10; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CHARGE DENSITY; CHARGE DISTRIBUTION; CORRELATIONS; ELECTRIC FIELDS; EQUATIONS; FRACTALS; GROUND LEVEL; LIGHTNING; SIMULATION; STOCHASTIC PROCESSES; TRAJECTORIES