Numerical Study on Securing Evacuation Environment Under Fire at an Inclined Tunnel Part

We have experienced severe fire accidents in tunnels, such as in the Mont Blanc Tunnel or Tauern Tunnel. These accidents triggered a series of studies for securing safe environments in case of tunnel fire. Plenty of research has been done so far, experimentally or numerically, on the phenomena of tunnel fire, and the behavior of smoke and heat has been discussed for the flat part of the tunnel. At the inclined part, however, the analysis is not sufficient, and it is necessary to be studied. The authors estimated the behavior of heat and smoke by fire at an inclined tunnel part by means of a 3-D numerical analysis. The analysis was done utilizing a freeware, named “FrontFlow/red” developed by a group at Tokyo University. The simulation results give a detailed flow field as well as heat and smoke distribution, which can be used to establish tunnel facilities as ventilation systems and their control, so that safe environments can be attained. It is also available to decide the interval of cross passages for evacuation.