On the development of a lightning leader model for tortuous or branched channels – Part II: Model results

The present model described in Part I of this work was applied to model stepped leaders. The obtained results for straight downward leader channels were compared to available measurements and estimations of different parameters of the lightning discharge reported in the literature. A good agreement between model results and previous works was found for the charge density in the lower part of the stepped leader, dart leader electric fields at ground level, stepped leader electric fields waveforms, average leader current, leader potential and striking distance to flat ground. Finally, the effect of tortuosity and branches on charge distribution, electric field and striking distance was evaluated. It was found that it is acceptable to assume straight channels to model tortuous leaders without branches and to estimate parameters such as the charge distribution along the channel, the mean electric field at ground level and the average striking distance to flat ground. On the other hand, the effect of the downward leader branches reduces the charge per unit length along the main channel significantly. Consequently, the assumption of unbranched leader channels to model natural branched discharges may lead to meaningful errors.