高超声速飞行目标尾焰红外辐射测量

为了研究超高声速飞行器发动机尾焰喷射高温高速气流的辐射特性，对尾焰成分CO₂及H₂O分子在4.3和2.7 μm大气窗口红外辐射波段进行了测量.利用高温燃气激波风洞模拟产生超高声速飞行器尾焰喷流，喷流速度M=5.5.实验中选用单元型InSb红外探测器，并利用黑体进行原位定标.测量距离为0.7 m，采用单透镜成像加光阑的方法收集光信号.实验中分别沿喷流方向喷流垂直方向进行了多点测量，通过定标结果反演得到尾焰在4.3和2.7 μm分别沿喷流方向和喷流垂直方向的光谱辐亮度和波段辐亮度分布，测量结果表明4.3 μm辐射强度及稳定性均高于2.7 μm. 

Infrared Radiation Measurement for Hypersonic Air Vehicle Exhaust Plume

In order to study the radiation characteristic of the high temperature and high velocity exhaust plume sprayed from hypersonic air vehicle, the infrared radiations at 4.3 and 2.7 μm atmospheric window which were emitted from CO₂ and H₂O molecules were measured. The simulated hypersonic exhaust plume jet was generated from hydrogen and oxygen detonation shock wave. The Mach number of exhaust plume was 5.5. Infrared detector in the experiment was the unit type of InSb which was calibrated in situ using standard blackbody. The measurement length was 0.7 m. A single lens and a diaphragm were used to collect the spectrum. Several points in the plume area were measured along the flow direction and the vertical direction respectively, and the corresponding distributions of radiance and spectral radiance were obtained. The final results illuminate that spectral radiance at 4.3 μm was stronger than that at 2.7 μm.