A software test-bed for electrical dynamics of direct cloud-to-ground and ground-to-cloud lightning flashes to aircraft: Initial results

Abstract

This work presents a self-consistent and self-contained model to study and analyse aircraft-lightning electrodynamics. An aircraft-circuit-model-based estimation of lightning currents is reported when the aircraft is struck by cloud-to-ground (CG) and ground-to-cloud (GC) lightning flashes. A distributed transmission line model for the aircraft and the return stroke channel of the lightning channel is used to simulate the return strokes of CG and GC flashes. It is observed that a higher magnitude of the rate of change in currents is produced due to the rapid discharge of electric charges on the lightning leader channel. Many GC return stroke currents eventually result in a steady state current along the channel resulting in a large build up of induced voltage in avionics. It is further observed that the severity of threat to airborne devices is great in the case of the initial wave-front of CG return strokes. Previous lightning return stroke simulation units failed to consider the inclusion of aircraft as part of the long CG or GC lightning channel, which is crucial when considering the engineering design of the aircraft body and the protection of internal electronics where shielding is weakened by weakly shielding aircraft bodies. We report here for the first time a computer software simulation tool for studying lightning-aircraft dynamics for engineering analysis and design.