涡扇发动机涵道比与红外辐射特征的关系实验

Experimental Research of Relation Between Bypass Ratio of Turbofan Engine and Characteristics of Infrared Radiation

研究了涡扇发动机涵道比变化对发动机后体空间红外辐射特征的影响。在实验中保持内涵气流流量、温度和外涵气流温度不变,单独改变外涵气流流量为内涵气流流量的0.4和0.5倍,实现内外涵道之间气流流量比的变化,即涵道比的变化;利用热电偶和傅里叶变换红外光谱辐射计分别测量喷管各部件壁面温度的变化和红外辐射特征。研究结果表明：随着涵道比的增加,冷气流量增加,在0°~90°方向内红外辐射均有减少,并且因为喷管壁面的有效辐射面的影响,在30°~80°方向降幅较大,在70°方向降幅最大。

Experimental research of influence of bypass ratio of the turbofan engine and the signature of infrared radiation was studied. In experiment, the mass rate and temperature of inner duct were kept constantly, the temperature of bypass duct was also kept constantly, but the mass rate of bypass duct changed from 40 percent to 50 percent of that of inner duct. It was the change of bypass ratio We measured the wall temperature of nozzle by using the thermocouple, and measured signature of infrared radiation by using FTIR. The result shows that as the increase of bypass ratio, in the direction of 0° -90° ,the infrared radiation reduce entirely, and because of influence of effective wall of radia- tion of nozzle wall, the direction of 30° ~ 80°, the decreasing amplitude is heavy, and the direction of 70~is the most.