Lightning Strike Probability Calculation Based on a Numerical Laplace Solver

Abstract

An electrostatic Laplace solver implemented with free-space boundary conditions is used to calculate electric field enhancements on the surfaces of metallic conductors. Predictions of field enhancements for individual, stand-alone buildings are compared to experimental observations relating lightning strike probability to building height. The accuracy of the numerical predictions at reproducing the observations is convincing. The numerical method is then applied to calculating lightning strike probabilities for buildings which are close together, which have superstructures on top, and which exist within an example city-scape. The predictions are interesting and exemplify the effects of mutual capacitance between structures, one of which is well known as “shadowing.” This study encourages additional experimental work quantifying lightning strike probabilities in more densely populated spaces, such as cities. In particular, the new model makes quantitative predictions about the lightning strike probability for closely spaced buildings of different heights, for buildings with peaked spires, and for buildings with other types of superstructures.