某型涡扇排气系统缩比模型红外辐射特性实验

针对某型涡扇排气系统构建1/5缩比模型,采用实验的方法验证了波瓣混合器能够降低涡扇发动机排气系统红外辐射.结果表明:相对于环形混合器,波瓣混合器使得排气系统出口尾焰温度降低11%左右,3～5μm波段红外辐射在各探测角度内降低7.3%～22.6%;涵道比从0.233增加到0.685,排气系统出口尾焰核心温度降低21%以上,红外辐射强度降低30%～59%;尾焰和排气系统内部壁面温度的降低使得排气系统红外辐射强度大幅度降低. 

Experiments on infrared radiation characteristics of exhaust system for a turbofan engine

One fifth scaled model was constructed for the turbo-fan exhaust system according to one-type engine for experimental research.The capability of infrared radiation suppression of the lobed forced-mixer was validated by some model experiments.The experimental data show the lobed forced-mixer can decrease the exhaust system infrared radiation.In detail,the lobed forced-mixer enhances the mixing between core flow and bypass flow to decrease the plume temperature by 11% and infrared radiation intensity by 7.3%～22.6% within 3～5 μm band as compared to confluent mixer.The bypass ratio was enhanced from 0.233 to 0.685,plume temperature reduced by 21% and infrared radiation intensity depressed by 30%～59% at different detected angles within 3～5 μm band.The plume and interior wall temperatures decrease accounts for the depression of exhaust system radiation intensity.