Author(s)

L. Courty, K. Chetehouna, J. P. Garo & D. X. Viegas

Abstract

In this paper the accelerating forest fire phenomenon for three real accidents is investigated. This phenomenon is studied using the hypothesis of the ignition of a Volatile Organic Compounds (VOCs) cloud accumulated in canyons. By heating a Rosmarinus officinalis plant in a specific hermetic enclosure, fourteen VOCs are identified and quantified as temperature functions. The theoretical flammability limits of those components are calculated by means of empirical correlations. Froude scaling law is applied to present laboratory results to find the concentrations of VOCs at canyon scale. The comparison of the flammability limits with the obtained concentrations shows that the emitted VOCs can lead to an accelerating forest fire. Keywords: Rosmarinus officinalis, VOCs emission, flammability domain, Froude scaling law, accelerating forest fire. 1 Introduction Forest fires cause important damages in terms of ecological and economical issues and human lives every year. Some fires with normal behavior suddenly start to propagate at unusual and very fast speed. They are called eruptive fires by Viegas [1], fires flashover according to Dold et al. [2] or accelerating forest fires by Chetehouna et al. [3]. The term eruptive refers to the continuous rise of the fire rate of spread and flashover to its unexpected character. There have been many accidents over the last half century where eruptive fires were reported [4–8]. In France, sixteen firefighters were killed during the

Keywords

Rosmarinus officinalis, VOCs emission, flammability domain, Froude scaling law, accelerating forest fire