Numerical investigation of externally venting flame characteristics in a corridor-façade configuration

Understanding of the physics and mechanisms of fire development and Externally Venting Flames (EVF) in corridor-like enclosures is fundamental to studying fire spread to adjacent floors in high-rise buildings. The main scope of this study is to investigate the burning behaviour of a liquid fuel pool fire in a corridor-like enclosure, to identify the key factors influencing EVF characteristics, EVF impact on façades and to assess the ability of currently available CFD tools to adequately describe corridor-façade fires. The Fire Dynamics Simulator (FDS) CFD tool is used for the numerical simulations which are compared and validated against medium scale experimental data on corridor-façade fire experiments. Experimental results suggest that in the interior of the corridor, good qualitative and occasionally quantitative agreement is observed for the gas temperatures. When the burner is positioned at the back of the corridor, resulting in increased temperatures at the interior, FDS generally under-predicts the combustion zone and the fire plume seems tilting at the rear of the corridor. The performance of the CFD tool in predicting EVF gas temperatures and heat flux to the adjacent façade is improved in larger opening sizes. Regarding the heat flux at the exposed surface of the façade, good quantitative agreement is observed, especially at lower heights near the opening.