Abstract: In a lateral smoke exhaust tunnel, the temperature and smoke flow are different because of the relative distance of fire location and the vents. Thus, FDS software was used to analyze the characteristics of temperature and smoke flow in the lateral smoke exhaust tunnel by changing the longitudinal location of fire sources. According to the results, the lateral vent has a cooling effect within a certain area, and the larger the smoke exhaust rate, the more obvious the cooling effect is; The farther the lateral vent from the fire, the more likely it is to be plug-holing; Increasing the smoke exhaust rate of the lateral vents can significantly reduce the longitudinal spreading distance of the smoke; Compared with the smoke exhaust rate, the fire source position has little impact on the total smoke exhaust efficiency, and only has an obvious impact on the smoke exhaust efficiency of the near vents.

Key words: tunnel fire, fire position, lateral smoke exhaust, temperature, smoke