Theoretical and experimental analysis of ceiling-jet flow in corridor fires

In tunnels or long corridors, the combustion products of the fire are confined to spread in one or two directions, forming a ceiling-jet flow. For safety assessment and emergency treatment, it is important to investigate and understand the behavior of the ceiling-jet flow. In this paper, a simple model has been presented, in terms of Richardson number and non-dimensional ceiling-jet thickness, to predict the temperature and the velocity of fire-induced ceiling-jet in a rectangular corridor. Besides, the location of hydraulic jump, occurring in ceiling-jet flow, has been estimated theoretically. In order to validate the theoretical predictions, a series of reduced-scale fire experiments were conducted in a 5 m long corridor. The predicted results, concerning non-dimensional excess temperature, agree favorably with experimental data in different fuels and heat release rates of the fire tests. Finally, the scaling issue has also been discussed and validated. (C) 2011 Elsevier Ltd. All rights reserved.