LAUSR

Abstract The vehicle being ignited in tunnel fire could disturb the temperature distribution and result in more serious hazards. However, the temperature profile about the tunnel fire with an ignited vehicle has not been clarified. This paper conducted a series of 1/6 small scale experiments with different heat release rates to investigate the vehicle ignition time delay and temperature profile. The longitudinal ventilation velocity varied from 0.5 m/s to 2.0 m/s, and the blockage-fire distance varied from 0.35 m to 1.6 m. The temperature and the ignition time delay were measured. Results show that the ignition time delay is shorter with shorter blockage-fire distance. The ignited vehicle results in the temperature hump and larger high temperature region at downstream. A modified model to predict the maximum temperature beneath the tunnel ceiling by considering the combined effect of longitudinal ventilation and blockage-fire distance is proposed. Finally, the predictions obtained by proposed model are compared with the experimental data and previous experiments.