Attractive radii of vertical and horizontal conductors evaluated using a self consistent leader inception and propagation model—SLIM

A self consistent lightning connecting leader inception and propagation model (SLIM) is utilized to study the attachment of lightning flashes to grounded structures and hence to evaluate the lightning attractive radii of vertical cylindrical structures and horizontal conductors as a function of height of the structure and peak current of the first return stroke. The attractive radius is defined as the maximum lateral distance from where the structure would be able to attract a down-coming stepped leader. The results are compared with the ones that one would obtain using Electro-Geometrical Method (EGM). The results show that for structure heights of the order of 30 m or less the attractive radii obtain from SLIM do not deviate significantly (i.e. the error is less than about 20%) from the EGM values. However, for taller objects SLIM predicts significantly larger attractive radii than EGM and the error increases with increasing height.

► EGM is an engineering model used to study lightning attachment to structures.
► SLIM is a physics-based model developed to study lightning attachment.
► In this paper attractive radii of structures to lightning flashes are calculated using EGM and SLIM.
► For structures lower than about 30 m the error in the attractive radii caused by EGM is about 20%.
► As the structure height increases SLIM predicts significantly larger attractive radii than EGM.