Flame spread and fire over cellulosic materials occur when the burning region supplies sufficient heat to the virgin solid to cause gasification. Under proper conditions, the reaction between the generated volatiles and the oxidant (air) may be sustained. The characteristics of the flame spread are therefore the result of heat and mass transfer processes as well as finite-rate gas phase chemical kinetics.
We describe here a new three-dimensional mathematical model to study flame spread over cellulosic fuels. Both the pyrolysis and burning of a vertical timber wall of a room and the turbulent flow, combustion and radiation in the room, are included. The predictions of this model have been compared with the results of an experiment. Excellent agreement has been achieved.