Computational Investigation of Effects of Expanded Metal Foils on the Lightning Protection Performance of a Composite Rotor Blade

Abstract

Lightning is one of the most important threats to the safe operation of an aircraft. Rotorcraft can experience lightning strikes on the main rotor blades and tail rotor blades which can seriously affect the rotorcraft and its components in several ways. When lightning strikes a rotor blade made of composite material, electrical-thermal multi-physical phenomena such as the Joule heating effect occur. In this study, an electrical-thermal computational simulation of lightning strikes on composite rotor blades was performed. The simulation analyzed various situations including the presence of a lightning protection system on the composite rotor blade. Emphasis was placed on the effects of geometric parameters of expanded metal foil on the lightning protection performance. In addition, the effects of curvature on thermal and electrical response were investigated. The thermally damaged area was found to substantially increase in inner layers compared to the flat plate case.