The spread of flame across a liquid surface I. The induction period

Abstract

Ignition at the surface of a flammable liquid and the subsequent spread of flame occur in three stages: an induction period, in which the liquid burns only within the ignition source; a transition period, in which the flame spreads from the source to the liquid surface; and a propagation period, in which the flame spreads across the liquid surface without reference to the source. An experimental investigation of the first of these stages in a system for one-dimensional flame-spread is described. Changes in the liquid and gas phases during the induction period have been followed and effects of depth, surface dimensions and initial temperature of the liquid on the duration of this period studied. A probable sequence of events determining the end of the induction period is deduced.