Fire Safety Science Digital Archive

A numerical study has been performed of combustible liquid behavior and temperature distribution in a solid-liquid mixed layer during flame spread over it when the main mode of heat transfer is convection. Heat transfer to the layer ahead of the leading name edge through the solid-liquid mixed layer is shown to occur mainly near the layer surface. It is found that the liquid motion ahead of the leading flame edge is induced by a combined force of surface tension and buoyancy. This implies the importance of buoyancy to understand the flame spread over a liquid soaked in porous solid. The predicted temperature distributions fairly well coincide with the experimental results, and it is found that the spread rate U can be approximately determined by selecting U which gives an appropriate value of the heat transfer from gas phase to the solid-liquid layer beneath the leading flame edge.