Experimental Study on Effect of Longitudinal Ventilation Velocity and Slope on Smoke Movement in Tunnels

Abstract

The slope effects on the movement of internal smoke cannot be ignored. Fire experiments in a small scale tunnel are conducted in order to observe the smoke movement in a tunnel with three kinds of slope (0%, 3% and 5%) under different longitudinal ventilation velocity, then find the correlation between smoke diffusion velocity and longitudinal ventilation velocity, and slope in tunnel by numerical fitting and dimensional analyses, finally conclude:(1) as longitudinal ventilation velocity increases, smoke diffusion velocity gradually decreases; (2) when longitudinal ventilation velocity is smaller, with the increase of slope, smoke diffusion velocity is gradually increasing; (3) when longitudinal ventilation velocity is large, slope to smoke diffusion velocity is not affected. These quantitative conclusions provide fire Prevention of the tunnel in city with a reference.