Heat and mass transfer in fires: scaling laws, ignition of solid fuels and application to forest fires

Abstract

Fire is a phenomenon that covers a multiplicity of scales depending on the different processes involved. Length scales range from the nanometres when addressing material flammability to the kilometres when dealing with forest fires, while time scales cover a broad spectrum too. Heating of structural elements can be measured in hours while characteristic chemical times for reactions do not exceed the millisecond. Despite these wide ranges, a series of simple scaling laws seem to describe well a multiplicity of processes associated with fire. In this paper, flaming ignition of a solid fuel will be presented within the context of general scaling laws and forest fires. Therefore, the case of highly porous vegetable fuels will be investigated to extend the theory to the forest fires application.