发动机舱油雾着火及火蔓延特性的数值模拟

为研究发动机舱内典型火灾规律，采用大涡模拟技术，针对某型发动机核心机舱建立了油雾火的火灾模型，研究舱内着火及火蔓延规律，分析不同泄漏位置及泄漏孔朝向对火焰传播及温度、热流分布的影响。结果表明：在舱内的通风热环境下，油雾泄漏会被引燃并稳定燃烧，中间有一定的潜伏期，火灾强度较大，破坏性严重；油雾火灾是典型的由通风控制的不充分燃烧过程，呈现一定的蔓延规律，火焰中心位于高速回流区，向引气口及尾部排气方向快速蔓延；不同泄漏位置及泄漏孔朝向对火灾的蔓延形态、温度及热流的分布有一定影响，其中泄漏位置对温度热流峰值影响较大，泄漏孔朝向对温度热流的分布影响较大。

Numerical simulation on fire and spread characteristics of oil spray in engine compartment

In order to study the typical fire in the engine compartment, the large eddy simulation technology was used to establish a spray fire model of engine core compartment. The fire and fire propagation process in cabin was studied, and the effects of different leak positions and spray orientations on flame propagation, temperature and heat flux distribution were analyzed. The result showed that the spray leakage led to ignition and stable burning in the ventilated heat environment of cabin. There was a certain incubation period during ignition, after getting a high intensive and serious destructive fire. Spray fire indicated a typical incomplete combustion process controlled by ventilation, presenting a certain law of propagation; the center of the flame was located in the high-speed recirculation zone, and it spread rapidly to the air intake and tail exhaust. Different leak positions and spray orientations had a certain impact on fire propagation, temperature distribution and heat flux. The location of the leak had greater influence on the peak temperature and heat flux, and the spray orientation had greater influence on temperature and heat flux distribution.