Influence of current direction in longitudinal ventilated road tunnels on the backflow of combustion Produits

The results of numerical modeling in longitudinal ventilated sloping road tunnels are given. slope the varies range 0-6%. geometry tunnel is as follows: length: 100 m; width: 8 height: 6 area seat fire: 16 m2. fire sized: 2.75x5.8x1.5 m central part tunnel. scenarios development 5, 10, 20, 30, 50 MW fires studied case positive and negative directional ventilation flows. time modelling was 120 seconds. problems were modelled with a volumetric grid method. cell dimensions were: 0.5*0.5*0.5 m. Virtual point measuring equipment used to record results. 4 groups devices that measured recorded air velocity, temperature, smoke densities. paper discusses cases algebraically summarizing fire-induced Based on modeling, we can out widely accepted indices critical velocity back-layering length inclined often give erroneous Therefore, strategies for emergency ventilation, indicators such back-separation should be caution.