Numerical Simulation and Analysis of Different Airflow Velocities in Tunnel Fire under Freeway

Tunnel has played an important role in the traffic and transportation network. Thanks to the noticeable improvement of computer technology, the simulation of computational fluid dynamics (CFD) has developed rapidly, which has been widely applied in the study of tunnel fire safety design. When the fire starts, people are vulnerable to poisonous and harmful smoke followed by high temperature, so the flow and temperature distribution of smoke must be explored. On this basis, the hazard of smoke and temperature can be analyzed and studied when a tunnel fire happens. The diffusion characteristics of smoke layer during a tunnel fire are obtained at different airflow velocities. Thus, this paper will build an original tunnel model, and employ fire dynamics simulator (FDS) for fire simulation and numeric simulation. Correspondingly, the harms to human being are analyzed while some advices on rescue and escape are put forward to provide the reference for escape and rescue from the tunnel under freeway.