涡轮冲压组合发动机燃油系统温升仿真研究

为了实现涡轮冲压组合发动机(简称组合发动机)燃油系统温升仿真计算,基于Flowmaster软件平台首次建立了组合发动机燃油系统温升仿真计算模型,为提高精度,根据试验数据自定义了航空煤油随温度压力变化的物性模块代替软件内置物性模块,基于此进行仿真计算得到不同工作模态下燃油系统温升情况。计算结果表明:涡轮模态工况下自定义物性模块计算得到的主要节点温升与软件内置物性模块相比总体偏低,且压力变化越大计算结果偏差越大;模态转换期间各子燃油系统流量迅速变化对燃油温度影响十分显著;冲压模态工况下燃油流量为2.68倍主燃烧室燃油流量时,可承受的最大发动机热负荷为400kW,最大飞行马赫数为5。实现了对发动机燃烧室入口燃油温度的预测和评估。

Simulation of Fuel System Temperature Rise in Turbine Based Combined Cycle Engine

In order to realize the simulation of the fuel system temperature rise of the turbine based com-bined cycle Engine (referred to as the combined engine), based on the Flowmaster software platform, the simulation model of the combined engine fuel system temperature rise was estab-lished for the first time. To improve the accuracy, the physical property module of aviation kerosene changed with temperature and pressure was customized based on the experimental data, instead of physical property module built-in the software. Based on this simulation cal-culation, the temperature rise of the fuel system under different working cases was obtained. The simulation results show that, under the turbine mode working case, the temperature rise of the main node calculated by the custom physical property module is lower than that of the software built-in physical property module, and the greater the pressure change, the greater the deviation of the calculation result; The rapid change of the sub-fuel system flow rate during the modal transition has a significant effect on the fuel temperature; Under the ramjet mode working case, when the fuel mass rate is 2.68 times of main combustion chamber, the maxi-mum bearable engine heat load is 400kW and the maximum bearable flight Mach number is 5. The prediction and evaluation of engine combustor inlet fuel temperature are realized.