长航时无人机燃油温度仿真及分析

Simulation and analysis of fuel temperature of long-endurance UAV

燃油温度是长航时无人机的关键性能。分析了燃油系统的典型组成,基于Flowmaster搭建完备的长航时无人机燃油温度仿真模型;进一步利用仿真模型,分析输油箱燃油初始体积、燃油初始温度和大气环境温度对巡航过程燃油温度的影响规律,并得到定量结论。分析结果显示,温度仿真值与实际值偏差不大于2%;输油箱的燃油温度始终高于供油箱的值,并且随着输油箱初始油量的减少,差值逐渐增大;输油箱初始油量为1/3油、2/3油和满油时,在达到热平衡前,输油箱燃油温度平均下降率分别为15.5℃/h、12.6℃/h和10℃/h;燃油初始温度越高、巡航时大气环境温度越低,均会提高燃油温度下降率。研究为长航时无人机燃油温度预测及燃油热沉分析提供指导。

Fuel temperature is a key parameter of the long-endurance UAV.The typical composition of the fuel system is analyzed,and a complete long-endurance UAV fuel temperature simulation model is built based on Flowmaster.The simulation model is used to analyze the influence of the initial fuel volume,the initial fuel temperature and the ambient temperature on the fuel temperature during cruising,and a quantitative conclusion is obtained.The analysis results show that the deviation between the simulated temperature value and the actual value was not more than 2%;the fuel temperature of the fuel delivery tank is always higher than that of the fuel supply tank,and the difference gradually increases as the initial fuel volume of the fuel delivery tank decreases;when the initial fuel volume of the fuel delivery tank is 1/3,2/3 and full,before reaching the thermal equilibrium,the average fuel temperature drop rate of the fuel delivery tank is 15.5℃/h,12.6℃/h and 10℃/h,respectively;the higher the initial fuel temperature and the lower the ambient temperature during cruising,the higher the fuel temperature drop rate.This study has provided guidance for fuel temperature prediction and fuel heat sink analysis of the long-endurance UAV.