大型飞机库内航空煤油泄漏蒸发扩散特征研究

Study on characteristics of evaporation and diffusion of kerosene leakage in large aircraft hangar

为有效预防大型飞机库内因航空煤油泄漏扩散导致的重大安全事故,基于国内典型大型飞机库空间结构,构建大型飞机库内航空煤油泄漏扩散过程的三维计算流体动力学(CFD)模型,采用组分输运模型和Standard k-ε的数值模拟方法,研究大型飞机库内航空煤油的泄漏扩散过程。结果表明:航空煤油蒸气在机库内蔓延扩散大致分为4个阶段:初始稀释、障碍累积、重力沉降和被动扩散阶段;机库内航空煤油蒸气的蔓延十分迅速,机库口蒸气体积分数在扩散200 s后超过爆炸下限;航空煤油蒸气主要分布于机库中下部位置,尤其是机库高度为4 m以下的空间遇火源极有可能发生燃爆现象。

In order to effectively prevent major safety accidents caused by leakage and diffusion of kerosene in large aircraft hangar,a three-dimensional computational fluid dynamics(CFD)model for leakage and diffusion process was established based on complex working conditions of typical large aircraft hangar in China.Then,component model and Standard k-εturbulent transport model were used for numeral simulation to study the whole process.The results show that kerosene vapor diffuses and spreads in four stages,namely initial dilution,obstacle accumulation,gravity settlement and passive diffusion.Its spread is very rapid,and its volume fraction at hangar entrance will exceeds lower limit of explosion after diffusing for 200 s.The vapor is mainly distributed in middle and lower part of hangar,especially below4 m where it will cause explosion when there is fire.