Abstract: The method of combining FDS simulation with theoretical calculation was used to study the influence of natural smoke outlet on the smoke exhaust effect of airport terminal based on 6 scenarios with different ratio of upper and lower opening area. The results showed that when the ratio of upper and lower open area is not greater than 1.8, with the increase of smoke outlet area, the indoor average temperature drops, and the height of smoke layer rises, the smoke exhaust effect becomes better and better. When the fire develops to 720 s, the average indoor temperature is still within the safe range, which has little impact on the evacuation of personnel. The theoretical model was established and compared with the simulation results. It is concluded that the theoretical model is applicable when the ratio of upper and lower opening area is 1.8.

Key words: natural exhaust smoke, smoke extraction effect, personnel evacuation, simulation analysis, theoretical calculation