Three-Dimensional Numerical Simulation of Lightning Discharge Based on DBM Model

The modeling and simulation of lightning discharge are very important for the lightning protection engineering and lightning research. In this paper, with the thundercloud electrostatic model and potential equation in the space, a three-dimensional(3-D) numerical simulation of lightning discharge at 50-m resolution was presented. The dielectric breakdown model(DBM) based on fractal theory and bidirectional leaders independent develop mechanism were employed to simulate the lightning leader progression. The effects of probability exponent eta and internal E-field E-in along the channel on the on-ground E-field distribution were analyzed respectively. The results show that the distribution of E-field at the ground level below the stepped leader is similar to Gauss distribution. The peak value of the E-field at the ground level increases with the probability exponent and internal E-field along the channel decreasing.