Abstract External combustion is the phenomenon of fire in the fire with the smoke out of the window and in the external combustion。 The particularity of ship space also needs further research and demonstration。 The for 27 meters traffic ship cabin, FDS software under the condition of different ceiling height of ship cabin fire development process based on a numerical simulation is performed。 Through the analysis of the temperature, smoke concentration and gas velocity, the external combustion phenomena in the process of the development of the fire were studied。 The conclusion is that:
(1) for ceiling vents of space and of the height of the roof is directly affected by the difference of flame combustion process, product formation changes the flame has great influence。
(2) in the special case of ceiling height may lead to combustion becomes unstable, flashover phenomenon appeared。
(3) for the spatial model of this study, the best ceiling height of 2 meters。
Key words: ship cabin; low ceilings; fire; external combustion