NUMERICAL SIMULATION OF THE BACKLAYERING EFFECT IN THE MEMORIAL TUNNEL TESTS

Road tunnels are key elements in the traffic net, especially for the long-distance road transport. In the case of fires, the control of smoke propagation becomes crucial since the major risk for people is smoke inhalation rather than the direct exposure to the fire. However, research in this field has been limited by the inherent difficulties of the problem, and so there are few experimental data available. This paper presents an investigation on the control of smoke propagation in road tunnels with a longitudinal air stream. The methodology is based on the numerical simulation of the air and smoke flows induced after the onset of localized fires of different magnitude. The general purpose of the paper is the refinement and contrast of a numerical procedure for the simulation of fire in road tunnels with natural ventilation, as the particular case with the most complex and restrictive conditions, and also the use of such procedure to study the backlayering effect. The obtained results were compared with the natural and longitudinal forced ventilation tests of the Memorial Tunnel program as well as with previous studies available in the scientific and technical literature.