低气压环境下飞机货舱轰燃规律的实验研究

为研究低气压环境下飞机货舱火灾发展至轰燃的内在规律，利用1/4体积标准飞机货舱在海拔4 260 m、气压60 kPa的环境下开展了一系列火灾轰燃实验。选择航空煤油作为主燃料，以单壁瓦楞纸箱被引燃作为轰燃发生的判据，研究低气压环境下不同火源尺寸对轰燃的影响。通过对飞机货舱内热烟气层平均温度、地板所受辐射热通量、燃料热释放速率和烟气体积分数的测量和分析，探讨低气压环境下轰燃发生的临界条件和表现形式。结果表明，火源尺寸的增大提高了轰燃发生的可能性和轰燃的剧烈程度，在达到引发轰燃所需的临界火源尺寸后，继续增大火源尺寸会使轰燃发生的时间提前；60 kPa压力环境下飞机货舱轰燃所需的临界条件为：上部热烟气层平均温度达到553.5 ℃，地板所受辐射热通量达到19.85 kW/m2。

Experimental study on flashover law of aircraft compartment in low pressure environment

In order to study the inherent law of the development of aircraft cargo compartment fire to flashover in a low-pressure environment, a series of fire flashover experiments were carried out using a 1/4-volume standard aircraft cargo compartment at an altitude of 4 260 m and an air pressure of 60 kPa. Jet fuel was selected as the main fuel, and the ignition of single-walled corrugated boxes were used as the criterion for flashover. The effects of different fire source sizes on flashover at low pressure were studied. Through the measurement and analysis of the average temperature of the hot smoke layer in the cargo compartment, the radiant heat flux on the floor, the fuel heat release rate and the smoke volume fraction, the critical conditions and manifestations of flashover under at pressure were discussed. The results show that the increase in the size of the fire source increases the possibility of flashover and the severity of flashover. After reaching the critical fire source size required for flashover, continuing to increase the fire source size will advance the timing of flashover. The critical conditions for flashover of the aircraft cargo compartment under a pressure of 60 kPa are: the average temperature of the upper hot smoke layer reaches 553.5 ℃, and the radiant heat flux received by the floor reaches 19.85 kW/m2.