Impact of a Change from an Aluminium- to a Composite-Type Aircraft on Wind-Assisted Aviation-Fuel Fire Dynamics - a Numerical Study

Abstract

This numerical study focuses on the impact of a composite-type aircraft on a large aviation-fuel fire in a moving fluid medium. A pyrolysis model over surface of condensed fuel and composite material is incorporated, allowing to investigate the roles of the wind conditions on fire growth, heat flux distribution and smoke products. The outcome of the study indicates that interaction between composite-type aircraft and fire environment combined with the influence of wind conditions affects dramatically the continuous flame shape and consequently, the distribution of the incident heat fluxes to the engulfed fuselage. An increase of wind speed results in an alteration of flame cover where the fire and fuselage are of comparable size. The highest toxic products such as carbon monoxide and soot occur on the windward side of the fuselage for a low wind speed, but on the leeward side of the fuselage for a medium or high wind one. The flame spread rate over a composite-type aircraft is almost equal in magnitude for a medium or high wind speed, but about a factor 4 increase of that to the low wind one. As a consequence, the fire power from a composite-type aircraft represents an increase of about 30% in comparison with that from aluminium-type one with a wind speed above 5 m/s.