Journal of Propulsion Technology ›› 2018, Vol. 39 ›› Issue (9): 2020-2027.

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Numerical Analysis for Effects of Fuel Mass Flow Rate on Performance of Air-Cooled Fuel Injectors

  

  1. School of Energy and Power Engineering,Beihang University,Beijing 100191,China and School of Energy and Power Engineering,Beihang University,Beijing 100191,China
  • Published:2021-08-15

燃油流量对气冷喷油杆性能影响的数值研究

刘友宏,郭 佳   

  1. 北京航空航天大学 能源与动力工程学院,北京 100191,北京航空航天大学 能源与动力工程学院,北京 100191

Abstract: Based on an air–cooled fuel injector in an afterburner of a turbofan engine, the temperature distribution was investigated under the influence of different fuel mass flow rates. A three-dimensional heat-liquid-solid coupling numerical simulation was conducted on the cruise state considering the multicomponent flow of combustion gas and air as well as the two-phase flow of fuel and combustion gas. The results indicate that when the fuel mass flow rate increases from 0.01kg/s to 0.07kg/s, average temperature of injectors (P1 and P2) and the heat shield decrease 4.6% and 2.8%, relatively lower fuel flow velocity leads to higher fuel temperature in the lower part of fuel injector P1, the temperature becomes homogeneous obviously as the increasing of fuel mass flow rate. The flow direction of cold air in the heat shield affects the temperature of fuel injectors observably. About 60% cold air flows out from the holes around the nozzles on the fuel injector P1, which causes the nozzles temperature 4%~7% lower than that of fuel injector P2.

Key words: Air-cooled fuel injectors;Coupling numerical simulation;Fuel mass flow rate;Two-phase flow

摘要: 以涡扇发动机加力燃烧室气冷喷油杆与隔热套为研究对象,分析燃油流量对气冷喷油杆和隔热套温度分布的影响,对其在巡航状态下进行了流热固耦合三维数值模拟研究,考虑了燃气、空气的多组分流动,以及燃油和燃气的两相流动。结果表明:随着燃油流量从0.01kg/s增加到0.07kg/s,两根喷油杆(P1和P2)平均温度下降4.6%,隔热套的平均温度下降2.8%;燃油在喷油杆下部流动速度过低,造成其下部温度较其他部分明显偏高,随着燃油流量而逐渐增加而改善;外涵冷气进入隔热套中的流动方向影响了喷油杆的温度分布;冷气从一号喷油杆侧的出口中流出的比例占到进入隔热套总冷气流量的60%左右,因此一号喷油杆的喷嘴温度比二号喷油杆的喷嘴温度低4%~7%。

关键词: 气冷喷油杆;耦合数值模拟;燃油流量;两相流