Study on combustion characteristics and smoke components of aviation cable under low pressure

In order to study the cruise safety of aircraft under high altitude and low pressure, the combustion characteristics of protective cover and insulation layer of waxy aviation cable FXL under normal pressure and low pressure are studied in this paper. The minimum ignition time (TTI), the maximum radiation temperature, the flue gas density and the mass loss rate of the protective cover and insulation layer of the waxy FXL aviation cable under 96 kPa and 61 kPa were studied. It is found that the minimum radiation temperature and TTI of the cable at 61 kPa are slightly higher than those at 96 kPa, but the activation energy is basically not affected by the air pressure. The smoke density and smoke composition under 96 kPa and 61 kPa were further studied, and it was found that the smoke density of the cable under 61 kPa sheath and insulation layer was lower than that under 96 kPa. The oxygen, carbon dioxide and carbon monoxide components in the flue gas were studied. It was found that the O₂ concentration of 96 kPa and 61 kPa cable protective sleeve and insulation layer decreased steadily at first and then increased. The change trend of CO₂ concentration was opposite, and the CO concentration showed a double-peak phenomenon. In addition, the mass loss rate (MLR) at different O₂ concentrations increases linearly with the increase in O₂ concentration. This work helps to understand the difference of combustion characteristics between 96 and 61 kPa, and provides a reference for improving civil aviation safety performance.