Numerical and analytical prediction of near tunnel wall fire flame length

In most fire accidents inside road tunnels, the fire starts from one or two cars and is then spread to other cars after sometime. The flame length is the most important parameter for controlling the spread of fire from the fire source to the nearbytrucks, therefore, knowledge of flame length and behavior is the most important challenge in controlling the fireconsequences. In the previous studies, fire is arbitrarily assumed at the center of the tunnel and some specific equations aredeveloped for those cases, however, in real conditions, the fire mostly takes place near the walls of the tunnel and the nearwall fire is very different from the central fires in a tunnel. In this study, analytical analyses and computational fluiddynamics simulation were performed through FDS software, to determine the length of the flame near the tunnel wall. Inaddition, support vector machines and fuzzy clustering model were used to develop a code to obtain better data from theFDS software. The results of empirical analyses indicate that in cases of near-wall fires, the fire flame is longer compared tothe cases where the fire occurs at the center of the tunnel. In a Fire with the power of ۱۳۰ kW, the ratio of flame length nearthe wall to the flame length at the center of the tunnel was equal to ۱.۷۴. The results of CFD simulations, with wood as thefuel source, indicate that any rise of fire heat leads to decreasing ratio of flame length in near-wall fires to the flame lengthat the center of tunnel until this ratio reaches unity

کلیدواژه ها:

FIRE ، FLAME LENGTH ، TUNNEL WALL ، CFD ، SUPPORT VECTOR MACHINES ، FUZZY CLUSTERING