Study of the influence of low air pressures on fire behavior and burn‐through of aircraft cargo liner

Abstract

Summary The cargo liner is the most effective and practical burn‐through barrier when a fire originating in the cargo compartment penetrates into the cabin. To investigate the low‐pressure effect on cargo liner burn‐through and assess the fire hazards during depressurization, a series of cargo liner burn‐through tests is conducted with a self‐designed burning‐resistant test rig. The experimental results indicate that the flame height increase caused by pressure decrease results in the direct contact between the fire and cargo liner at the ceiling. The ceiling jet formed beneath the liner panel with increasing flame height enhances the contact with the cargo liner, thus increasing the flame horizontal sectional area above the fuel pan. The thermal feedback from the cargo liner notably affects the fire, and the closer cargo liner generates greater thermal feedback. Lower‐pressure conditions result in a low mass burning rate and long combustion time. The curve of the mass burning rate is smooth, and the flame fluctuation frequency is low under low pressures. Low pressures cause an increase in flame height and high‐temperature flame region, which causes the high‐temperature flame region to remain in contact with the liner panel for an extended time, resulting in the liner panel burning through more readily. The post‐fire panels under low pressures attain high rear temperatures and large dilation and carbonization areas, demonstrating that the burning damage of the liner panel is more serious under low pressures.