Flame spread behavior characterization of discrete fuel array under a forced flow

Abstract

The forced flow driven flame spread behavior along an array of discrete wooden fuel elements was experimentally investigated, which could be an important step to understanding the flow-flame interactions that govern fire spread. Fuel arrays with five different spacings (0.75, 0.875. 1.00, 1.125, and 1.25 cm) were subject to flow speeds ranging from 2.2 to 4.3 m/s at approximately 0.2 m/s intervals. For spacing-flow speed conditions tested in the current study, the flame spread behavior was categorized into three different regimes, continuous, discrete, and quenching, and the regimes were presented in a flammability map. Visual analysis of top and side view video data were used to describe the changing flame behavior and increasing discretization of the overall flame structure as the flow speed increases. An analysis of the fluid mechanics and heat transfer conditions revealed a correlation between the Stanton number (St), the Damkohler number (Da), and the onset of flame instabilities and quenching. © 2020 The Combustion Institute.