Study On Combustion Properties Of Typical Interior Materials Of Aircraft Under Low Ambient Pressure

The combustion characteristics of aircraft interior materials such as aircraft carpet and seat fabric under low and normal pressures were studied supported by National Science Foundation of China（Grant No.U1633203）.There were three main research contents in this paper:Firstly,the variations of smoke density,O₂,CO₂ and CO content were studied when the aircraft interior materials combusted under low pressure environment.In addition,the toxicity of CO was investigated using FED disability model under low pressure.Secondly,the effects of external heat source radiation temperature on the ignition time of aircraft interior materials were investigated under the conditions of low pressure and normal pressure.Thirdly,the effects of oxygen volume concentration and the rate of gas flow on the combustion characteristics of the aircraft seat fabrics were also discussed.The main results of this work were listed as follows:First,the smoke densities of aircraft carpet and seat fabric varied obviously under low pressure,and which reached the maximum（about twice of normal pressure value）rapidly and then maintained.In addition,the content of O₂ in the surroundings decreased firstly then increased.Under low pressure,the decreased rate of O₂ content was faster and the minimum value was lower than which under normal pressure.The variation of CO₂ concentration was opposite trends compared with O₂.At the beginning,the CO concentration was increased slowly and the value was slightly smaller than normal pressure.Then,the rate of CO content increased sharply,and which reached the maximum value.It was much larger than the normal pressure value,and finally decreases slowly.The results of CO FED disability evaluation under low and normal pressure shows that the CO toxicity test meets standard under normal pressure,while it has a dangerous level under low pressure.Another,it has a greater impact on the ignition time（the ignition time was shorter）under low pressure when the external heat radiation temperature was between 500⁷00℃.While the external heat radiation temperature was between 800¹000℃,the ignition time at normal pressure and low pressure decreases and tends to be equal.Third,it has a greater inhibitory effect on the combustion of the material under low pressure when reduce the ambient oxygen concentration.The mass loss rate of the sample was greater under low pressure when it was burning same length.