Citation

Woycheese JP, Pagni PJ, Liepmann D. J. Fire Prot. Eng. 1999; 10(2): 32-44.

Copyright

(Copyright © 1999, SAGE Publishing)

DOI

10.1177/104239159901000203

PMID

unavailable

Abstract

This paper is one of a series on brand lofting and propagation. Here, spherical brand propagation in a constant ambient wind is addressed. Maximum propagation distances are calculated for wooden brands with diameters up to 0.18 m, which are lofted above axisymmetric pool fires with heat release rates, Qo, between 1 MW and 3 GW. Winds of 1.8 m/s ≤ Uw ≤ 92 m/s are considered. A maximum propagation distance equation is developed as a function of Qo, Uw and wood type, or β. Cedar brands (β = 1), lofted by fires with Qo = 1 MW, 50 MW and 1 GW, travel a maximum of 49 m, 290 m and 1100 m, respectively, in 10 m/s winds before landing at burn out. Brands between a "collapse" diameter, dcol = 0.49 Q0 0.269 β0.782, and a maximum loftable diameter, do,max = 0.454 β Q0 0.04, propagate the same maximum distance, since the larger brands move slower and therefore have more time to combust. Hence, only brands with 0 ≤ d ≤ d col need be studied for given Qo, Uw and β.

Language: en