A Model for Ceiling Flame Spread

Abstract

In this paper, an approach for modeling flame spread beneath a pyrolysing surface of a charring solid is developed. The presented model consists of a one-dimensional ceiling flame spread submodel based on SQW equation developed for upward flame spread, and a one-dimensional pyrolysis submodel. These two submodels are numerically solved using a conditionally stable forward Euler method and a Runge-Kutta method for stiff problems, respectively. The existing experimental data (the ceiling flame spread beneath medium density fibreboard (MDF)) are used for comparison to validate the model. The comparison results show that the predictions of the maximum distance of ignition front and the heat release rate per unit width are in good agreement with the experiments. Discussions with the effects of the heat of gasification on the flame length, the pyrolysis front and the heat release rate indicate that it is a very important parameter in the present model.