Effect of Blockage and Longitudinal Ventilation on Longitudinal Temperature Distribution in Tunnel With the Unpowered Ventilation Cap

Urban tunnel fires often produce huge smoke and cause serious consequences. The temperature attenuation of fume in fire is very important for fire prevention and rescue. In this paper, a 1/15 reduced‐size tunnel test platform is utilized to probe the impact of blockage on longitudinal temperature attenuation in the tunnel under the action of the unpowered ventilation cap. The results demonstrate that the tunnel with the unpowered ventilation cap has a higher overall longitudinal temperature and a greater longitudinal temperature attenuation coefficient than the tunnel lacking the unpowered ventilation cap. In light of the experimental conclusions, the forecasting model of the maximum ceiling temperature is improved by introducing correlation factors, which indicate an excellent correlation with the current experimental conclusions. The research outcomes have paramount significance for fire rescue and safety prevention and have certain reference values for the layout of ventilation devices in tunnels.