This paper presents the results of a combined experimental and theoret
ical study of piloted ignition of cellulosic materials. The main objec
tive is to present an engineering solution to the piloted ignition pro
blem for wood exposed to radiant heat in a bench-scale piloted ignitio
n test. This has been motivated by the need to have simple models of i
gnition for use in a computational fluid dynamics (CFD) model of fire
spread and extinguishment in building fires. The experiments were cond
ucted on oven-dry and moisture conditioned samples of three wood speci
es using a cone calorimeter. As expected, the experimental data reveal
ed that the effect of moisture content on the piloted ignition process
is significant. It was also found that the ignition temperature depen
ds on the external heat flux, which supports other recent studies. Bas
ed on the experimental observations, an approximate analytical equatio
n was derived and then used for correlating the ignition data, as well
as extracting the piloted ignition properties. The chief distinguishi
ng feature of the present equation over other similar equations is tha
t it takes into account the variation of the ignition temperature with
external heat flux. (C) 1997 Elsevier Science Ltd.