Fine fuel particle heating during experimental laboratory fires

Abstract

Fuel particle temperature measurements were related to measurements of particle irradiance and impinging gas temperatures during seven fire spread experiments at the U.S. Forest Service Fire Sciences Laboratory, Missoula, Montana. Fine particle temperature increases corresponded to pulses of impinging hot gases and thus suggested convection as the primary heat transfer mechanism responsible for particle ignition. An analysis using the flux-time product correlation (FTP) indicated that flame radiation was insufficient to pilot ignite fuels for fire spread. A numerical modeling examination of fine particle heating indicated flame radiation was insufficient for particle ignition and convection heat transfer from flame contact was the primary heating mechanism leading to particle ignition.