Numerical Simulations of Dynamics of a Tunnel Fire

Study of fire in a tunnel is very important for fire safety. Increasing concerns over terrorism put a lot of focus on the fires in tunnels as they are used extensively in mass transit systems all over the world. A lot of experiments have been carried out to study the fire hazard, smoke movement, and the effects of ventilation on fire behavior. In this paper, dynamics of a ventilated tunnel fire have been simulated using Computational Fluid Dynamics (CFD) Software, CFX 5.6, from Ansys Inc. Simulations considers different models of turbulence and radiation heat transfer. Combustion of methane is modeled using the chemical reaction schemes available in the CFX software. Two turbulent models, k–ε and Shear Stress Transport, are considered. Radiant heat exchange between the species is modeled using P1 model available in CFX 5.6. The results of the simulation have highlighted the effects of ventilation on the fire and movement of harmful gases such as carbon monoxide and nitrogen oxide. Comparison of simulated temperature fields and flame shape with the experimental data has shown good agreement.