Study on smoke diffusion and ceiling temperature distribution in the V-shaped tunnel fire scenario

Abstract

In this paper, numerical simulations are conducted to study the smoke diffusion characteristics in the V-shaped slope tunnel with different slopes. The smoke diffusion characteristics and the ceiling temperature distribution with three kinds of heat release rates (HRR) and three kinds of slopes are considered without mechanical ventilation. The simulation results show that the smoke diffusion symmetrically on both sides of the symmetrical V-shaped tunnel. The smoke diffusion speed is mainly affected by the HRR, while it is less affected by the slope. The smoke diffusion speed increases with the increase of HRR. The maximum ceiling temperature increases with the increase of HRR and decreases with the increase of slope. The HRR is constant, the ceiling temperature decreases with the increase of the slope within 150 m away from fire source. Beyond 150 m from fire source, the ceiling temperature distribution are in opposite tendency and the overall temperature has a little difference between both sides of V-shaped tunnel.

Keywords

• v-shaped slope tunnel
• smoke spread characteristics
• temperature beneath ceiling