USE OF MOBILE FANS IN TUNNELS

Several accidents have recently occurred, revealing how deadly fires in tunnels can be. Tragic events such as the one in the Mont Blanc tunnel or the St. Gotthard tunnel showed how hard it is for the first brigade to intervene with such fires. New equipment is now available to cope with fires in tunnels, namely, mobile fans placed at one end of the tunnel. The aim of this study is to investigate the limitations of this technique by using a computational fluid dynamic code. First, comparison was carried out with 'cold' experiments performed in two existing tunnels in Europe. This was followed by a corresponding simulation of a 15 MW fire located in the middle of two trains at the centers of the tunnels. Buoyancy effects due to the slope of the tunnels were considered in the computational fluid dymamic simulations.