Suppression effectiveness of water sprays on accelerated wood-crib fires

Solid-fire extinguishment by water sprays has received remarkable attention over the decades. Though several approaches have been taken to understand the important physical phenomena, empirical correlations remain very common in discussions of these fires. Historically, wood-cribs have offered an important means by which to study the extinguishment of combustible solids, as their simple and well-defined structure lends a degree of repeatability to experimental investigations. Therefore, several classical experiments in this area focus on wood-crib fuel packages [1-3]. The primary objective of this mainly experimental study is to determine the relationship between the water flux applied to a burning wood crib and the total damage sustained by the crib, as assessed by the crib’s mass loss. A thermodynamic discussion of the potential cooling mechanisms also provides physical insight into the suppression results. As an additional feature of the present work, an experimental characterization of the water mist spray was performed in terms of flux and drop-size distribution, following previous spray studies [4]. Moreover, additional parameters were investigated to better understand the wood-crib fire dynamics (e.g., air entrainment at the lateral surface and heat release rate).