Modeling of Lightning Direct Effects - Interaction of Continuing Current with Aluminum Skins

Y. Kostogorova-Beller[1], and R. Collins[2]
[1]National Institute for Aviation Research, Wichita, KS, USA
[2]Hawker Beechcraft Corporation, Wichita, KS, USA

An interaction of aluminum aircraft skins with a laboratory-simulated, low-level, long-duration, continuing current representative of a natural lightning flash was modeled with COMSOL Multiphysics. For the analysis of the lightning direct effects on aircraft, the external environment is represented by the idealized current components. Particularly Component C is used and is characteristic of current with unidirectional waveform of 200-800 Amps with durations of 0.25-1 seconds. It is assigned to transfer 200 Coulombs of charge which may result in a melt-through or hot-spot formation that can manifest into fuel ignition in metal skins depending on material’s thickness, electrical conductivity, and surface finish. The melt-through areas were documented and the interior-surface temperature rise was monitored with infrared thermometers. The experimental data was utilized in an electro-thermal steady-state analysis to develop a 3D pattern of current density and temperature distribution in panels based on ARP 5412 continuing current lightning waveforms.