客机火灾条件下下降角度对舱内烟气温度分布规律的影响

Influence of descent angle on cabin flue gas temperature distribution under fire condition of passenger aircraft

为探究飞机客舱火灾紧急下降过程中,不同下降角度对火灾烟气运移的影响,运用FDS模拟软件建立波音737-400型飞机客舱全尺寸模型,分析7种飞行角度下客舱火源前、后部区域顶棚最高温度、客舱内部纵向温度场分布以及烟气蔓延过程。结果表明,飞机由巡航改为紧急下降状态会导致客舱内部出现烟囱效应,客舱不同区域烟气温度分布规律受下降角度影响表现不同,随着下降角度的增加,客舱前部烟气运移受阻明显,同一位置顶棚最高温度逐渐降低,温升速率与下降角度呈反比关系;客舱后部烟气在烟囱效应下迅速聚集、下沉,下降角度对其顶棚最高温度及温度分布的影响逐渐弱化。

In order to explore the influence of different descent angles on fire smoke migration during emergency de-scent of aircraft cabin,FDS simulation software was used to establish a full-size model of Boeing 737-400 aircraft cab-in,and analyzed the maximum ceiling temperature in front and rear area of the cabin fire source,longitudinal tempera-ture field distribution in the cabin and smoke spreading process under 7 different flight angles.The results show that the transition from cruise to emergency descent will lead to the chimney effect in the cabin,and the flue gas temperature distribution law in different areas of the cabin is affected by the descending angle differently.With the increase of de-scending angle,the flue gas migration in the front of the cabin is blocked obviously,and the maximum ceiling tem-perature in the same position gradually decreases,in addition,the temperature rise rate is inversely proportional to the de-scending angle.The flue gas at the rear of the cabin rapidly accumulates and sinks under the chimney effect,and the in-fluence of the descending angle on the ceiling maximum temperature and temperature distribution is gradually weakened.