Experimental study on behavior of sidewall fires at varying height in a corridor-like structure

Abstract

A set of experiments on sidewall fires was conducted in a small-scale corridor-like structure. The mass loss rate, ceiling jet flame length and maximum ceiling jet temperature were investigated by correlating with the distance between fire source and ceiling. The results show that as the effective ceiling height decreases, the mass loss rate increases due to the enhanced radiation heat feedbacks from the ceiling and ceiling jet flame to the fuel surface. The mass loss rates are higher for the pans with long edge attaching sidewall compared to those with short edge attaching sidewall, due to the enhanced sidewall confinement effect. A simplified equation for predicting the mass loss rate per unit area is developed involving the dimensionless effective ceiling height and the length ratio of pan edges attached and perpendicular to the sidewall. Besides, a correlation is established between the dimensionless longitudinal length of ceiling jet flame and the dimensionless heat release rate by taking into account the effects of heat release rate, effective ceiling height, pan size and layout. The maximum ceiling jet temperature rise for intermittent flame hitting the ceiling can be expressed using the similar form as the McCaffrey’s model. A modified correlation for the maximum ceiling jet temperature by taking into account the effect of the pan layout and the aspect ratio of the pan edges is proposed.