Initiation of fire growth on fuel-soaked ground

Abstract

The problem of initial fire spread over fuel-soaked ground was experimentally modeled in detail using a bed of glass beads saturated with n-decane as the fuel. After igniting the center of the horizontal fuel-soaked surface, the flame spreads concentrically and formed a growing centered flame pillar. The radial spread velocity of flame pillar base accelerated during the initial fire growth stage. The dominant mode of heat transfer controlling the spread of the flame pillar base was by flame radiation. The present study shows some important and fundamental characteristics of the growing flame pillar by using the direct video movie, Schlieren photography, particle trace technique, radiation flux measurement and temperature measurement. The study considers the spread velocity of the flame pillar base, behavior of the flame pillar, luminous height of the flame as a function of flame base diameter, frequency of flame height fluctuation as a function of flame base diameter, flow pattern of flame-induced convection, variation of flame radiation heat flux with elapsed time, and profile and fluctuation of local gas phase temperature on the axis of flame pillar. From the point of view of prevention of subsequent fire hazard, the present study discusses some important experimental results for the development of fire size and flame radiation during the initial stages of a growing flame pillar on the ground which has been soaked by spilled liquid fuels.