Two-dimensional simulation on the glow to streamer transition from lightning rods

In the past twenty years, there has been a growing concern regarding the effect of space charge produced by glow corona on lightning attachment. Several studies have been reported in the literature to evaluate the generation and drift of space charge generated by glow corona from the top of high grounded objects under thunderstorm conditions, using one (1D) or two (2D) dimensional simulations. Unfortunately, the actual transition from glow corona to streamers cannot be numerically evaluated in these studies since the ionization layer was ignored. Thus, a fully 2D detailed evaluation of the glow corona to streamer transition in air is reported, which considers the non-equilibrium ionization layer around a scaled lightning rod. The transition criterion is obtained by changing the applied voltage with different rise rates (dV/dt) after a stable glow corona is formed. The discharge currents as well as the distributions of positive ions, electrons and electric field during the transition of glow corona to streamers are presented. Based on the simulation results, a case study regarding a real lighting rod under thunderstorms is performed. The analysis indicates that streamers can be incepted in the presence of glow corona from both the tip and body of lightning rods under the influence of distant downward stepped leaders.