二元喷管热喷流的红外光谱辐射特性实验

Experiment on spectral infrared radiation characteristics of exhaust jet from 2D nozzle of turbofan engine

为了获得涡扇发动机二元喷管热喷流的红外辐射特性,分别对喷口面积相等且宽高比分别为1,4,8,12和16的二元喷管的热喷流的红外辐射特性进行了测试,并与轴对称喷管进行了对比。喷管内涵通道的气流温度为500℃,外涵通道的气流温度为环境温度,内、外涵气流的流量比为1：3。通过实验,获得了各个喷管的热喷流在3-5μm波段的红外光谱辐射强度分布和积分强度。结果表明,采用宽高比大于1的二元喷管能够有效降低热喷流的红外辐射,但是在宽高比大于8以后二元喷管热喷流的红外辐射不再随宽高比的增加而明显减小。

The spectral infrared radiation of the exhaust jet from 2D nozzles of turbofan engine were measured. The aspect ratio of 2D nozzles are 1, 4, 8, 12 and 16, respectively. The measured spectral intensity and its integral in the wave band of 3 - 5μm was presented, and compared with that from the axisymmetric nozzle, with the same exit area. The temperature of the inner channel flow was 500℃. The temperature of the outer channel flow was the same as the environment. The flux ratio of inner to outer channel was 1 ： 3. The result show that the 2D nozzle, with aspect ratio larger than one can dramatically suppress infrared radiation of the exhaust jet. The suppression effect is more effective as the aspect ratio increases. However, while further increasing aspect radio to be greater than 8, it will no longer lead to obvious suppression of infrared radiation.