Abstract: The natural smoke exhaust effect of two relatively open exterior windows in the vestibule with an area of 6 m 2 under different environmental wind field conditions is studied by means of the fire experiment and FDS.Through the analysis of the distribution of temperature and smoke density, it is found that the main factor affecting the smoke exhaust is the window area. The influence of wind speed on the temperature in the lower part of vestibule is larger than that in the upper part. With the increase of wind speed, the temperature in the upper part decreases slowly and linearly, while the temperature in the lower part increases with the deposition of exhaust gas. According to the simulation results, when the wind speed increases, closing the windward window can improve the smoke settlement phenomenon, reduce the smoke temperature in the lower layer, which is conducive to the safe evacuation.

Key words:  vestibule, natural smoke, fire experiment, numerical simulation