航空发动机排气系统红外辐射特性数值研究

Numerical study of infrared radiation characteristics for aero-engine exhaust system

为深入了解航空发动机排气系统各部件对其红外辐射特征的影响,利用CFD/IR数值模拟方法研究了各部件发射率和内锥体温降对排气系统红外辐射特性的影响。结果表明:中心锥、低压涡轮和喷管扩张段是影响排气系统3～5μm波段红外辐射强度的关键部件,喷管扩张段和喷管外罩是影响排气系统8～14μm波段红外辐射强度的关键部件;喷管收敛段发射率的改变对排气系统红外辐射强度几乎无影响。所得结论具有较高的工程应用价值,可为发动机红外隐身设计提供参考。

In order to obtain the effects of each part of engine exhaust system on the infrared radiation char-acteristics,the effects of emissivity and temperature reduction of the cone on the infrared radiation charac-teristics of engine exhaust system were investigated based on CFD/IR numerical calculations.The results in-dicate that the cone,low pressure turbine and nozzle expansion section are the key parts for 3~5μm wave-band infrared radiation intensity of exhaust system;the nozzle expansion section and cover are the key parts for 8~14μm waveband infrared radiation intensity of exhaust system;the emissivity change of nozzle conver-gent section has almost no effect on the infrared radiation intensity of the exhaust system.The findings are valuable for engineering application which can be referential for aero-engine infrared radiation design.