飞机燃油温度仿真及应用

为研究飞行过程中燃油温度变化规律,采用热网络法建立油箱热模型,并在Matlab/Simulink软件平台上输入与飞行试验相对应的边界条件以验证模型可信度,在此基础上,分析了整个航程中各油箱隔舱燃油温度的变化规律。结果表明:该计算方法和仿真模型具有较高的可信度,试验值与计算值两者误差超过1.67 K的时间段中,模拟温度比试验温度高;多数航段内机身油箱燃油温度处于高位,为适航符合性审定重点关注对象,代表着整个燃油箱系统的可燃性暴露时间水平, 以巡航结束阶段为例,标准天长航程下机身油箱燃油温度比机翼油箱燃油温度平均高出25 K,标准天短航程下机身油箱燃油温度比机翼油箱燃油温度平均高出7 K,热天短航程下机身油箱燃油温度比机翼油箱燃油温度平均高出12 K;机翼油箱燃油温度在飞机下降阶段回升幅度较大,其可燃性暴露时间主要集中在航程结束阶段。

Simulation and application of aircraft fuel temperature

In order to study the fuel temperature change rule during flight, a thermal network method was adopted to establish a thermal model of the fuel tank, and the boundary conditions corresponding to the flight experiment were input into Matlab/Simulink software platform to verify the credibility of the model. Based on that, the change rule of fuel temperature in each tank compartment throughout the voyage was analyzed. Results showed that the calculation method and simulation model had high credibility; when the error between the experimental value and the calculated value exceeded 1.67 K, the simulated temperature was higher than the experimental temperature. The fuel temperature in the fuselage tank was high in most sections, representing the flammability exposure time level of the entire fuel tank system as the focus of attention for airworthiness compliance certification. Taking the cruise end stage as an example, the fuel temperature of the fuselage tank was 25 K higher than the wing tank fuel temperature on the standard long-range flight, the average temperature was 7 K higher on the fuselage tank fuel temperature than the wing tank, the hot day was shorter during the voyage, and the fuel temperature of the fuselage tank was 12 K higher than that of the wing tank. The fuel temperature of the wing fuel tank rebounded greatly during the descent phase of the aircraft, and its flammability exposure time was mainly concentrated at the end of the voyage.