An experimental investidation on vehicular blockage effect on the maximum smoke temperature in tunnel

Abstract

Researchers are motivated to study tunnel fires because of the increasing number of large-scale incidents in urban tunnels. When a fire occurs, most likely there are vehicles which get stuck in the tunnel. The stuck vehicles act as additional barriers against the flow of smokes. The effect of blockages on the maximum temperature of smoke which has not received considerable attentions in most of the previous investigations, is studied in this research. A set of scaled-down experiments was performed in a model tunnel [3 m (length) × 0.6 m (width × 0.96 m (height)]. The variables in this section are ventilation velocity, heat release rate (HRR) and blockage percentages. Gasoline was used as fuels in rectangular pools to generate a heat source. The influence of blockage percentages on the maximum smoke temperature beneath the ceiling has been investigated by improving the model of maximum smoke temperature published earlier by Li using local velocity near the fire source. This analysis reveals that the modified model of maximum temperature, which considers the effect of vehicular obstacles, could estimate experimental results with greater accuracy.