Study on the Length of the Near -Fire Source Area in Long and Narrow Space.

This paper studies the fire spread in horizontal long and narrow space with urban tunnels as the background. The length of the near-fire source area is a key factor to study tunnel fire with hybrid field-network simulation method. The length is influenced by the temperature difference in the cross section and the rate of temperature difference in long and narrow space with different tunnel widths and heat release rates. The theoretical analysis and numerical simulation methods are used to consider the influence of long and narrow space's width, heat release rate, effective ceiling height and the distance from fire source on the smoke propagation. The results show that the length of the near-fire source area are basically affected by the cross-sectional area of the long and narrow space and the heat release rate. For the type t2 ultra-fast fire model, when the heat release rate is 15MW and the length of the near-fire source area is 115m, the smoke flow can be fully developed. Finally, this paper proposes a prediction model for estimating the length of the near-fire source area. [ABSTRACT FROM AUTHOR]