Purpose

The assessment of fuel tank flammability exposure time for transport aircraft is one of the indispensable links in the airworthiness certification process. According to published literature, many factors can affect the flammability exposure time, while systematic analysis and calculations addressing these factors are in shortage.

Design/methodology/approach

Based on the requirements for airworthiness certification of domestic large aircraft, the fuel tank flammability exposure time of transport aircraft is calculated with the Monte Carlo evaluation model specified by Federal Aviation Administration. Meanwhile, the influence of each input parameter on the flammability exposure time is obtained by taking user input parameters in the model as independent variables and freezing other factors at the same time. The significance degree of the influence of each factor is discussed by the orthogonal test method. Subsequently, the interaction between the input parameters is studied by response surface method, and a multiple linear regression method is used to establish the functional relationship between the flammability exposure time and the influence parameters.

Findings

Research studies show that among the many factors that affect the flammability exposure time, the cruising Mach number, the equilibrium temperature difference and the maximum range are more significant and much attention should be paid to in the airworthiness certification; although there are interactions among various factors, they have different influence on the flammability exposure time, among which the interactions between maximum range and equilibrium temperature difference are the most significant compared with others; established by applying multiple linear regression equation and based on the test data of response surface method, the functional relationship between flammability exposure time and influence parameters is of sufficient reliability and can be used for preliminary prediction of fuel tank flammability exposure time for transport aircraft.

Originality/value

The research achievements of this paper can provide much useful reference for the certification of domestic large aircraft.

中文翻译：

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运输机燃油箱可燃性暴露时间影响因素研究

目的

运输机燃油箱可燃性暴露时间评估是适航审定过程中必不可少的环节之一。根据已发表的文献，影响可燃性暴露时间的因素很多，而针对这些因素的系统分析和计算却很缺乏。

设计/方法/方法

根据国内大型飞机适航审定要求，采用美国联邦航空局规定的蒙特卡罗评价模型计算运输机燃油箱可燃性暴露时间。同时，将模型中的用户输入参数作为自变量，同时冻结其他因素，得到各输入参数对可燃性暴露时间的影响。采用正交试验法讨论各因素影响的显着程度。随后，通过响应面法研究输入参数之间的相互作用，并采用多元线性回归方法建立可燃性暴露时间与影响参数之间的函数关系。

发现

研究表明，在影响可燃性暴露时间的众多因素中，巡航马赫数、平衡温差和最大航程更为显着，在适航审定中应予以重视；各因素之间虽然存在交互作用，但对可燃暴露时间的影响不同，其中最大射程与平衡温差的交互作用最为显着；应用多元线性回归方程，基于响应面法的试验数据建立，

原创性/价值

本文的研究成果可为国产大飞机的审定提供有益的参考。