某喷气发动机尾焰的中长波红外辐射分析和比较

利用中波红外和长波红外热像仪对某型 喷气飞机发动机尾焰的红外辐射特性进行了测量，得到了3～5 μm 和8～12 μm波段的尾焰辐射亮度分布。结果表明，从飞机 尾向上观测到的中波红外和长波红外尾焰均成对称分布，前者的最高辐射亮 度和尾焰面积分别是后者的4.6倍和2.1倍；从飞机侧向上观测到的 中波红外尾焰的最高辐射亮度、尾焰长度和面积分别是长波红外尾焰 的2.2倍、3.8倍和5.7倍，前者的优势非常明显。另外，受高温尾焰加热的影响，尾 焰周围空气的温度明显上升，使其辐 射亮度高于其他背景的辐射亮度。本文获得的测量结果对尾焰红外辐射特性仿 真和计算研究具有一定的参考价值。

Analysis and Comparison of Middle and Long Wave Infrared Radiant Intensity of Jet Engine Exhaust Plume

The infrared radiation characteristics of exhaust plume from a certain type of jet engine were measured by using mid-wave and long wave infrared thermal imagers. The radiation intensity of the exhaust plume in mid-wave and long wave bands was obtained. The result showed that both mid-wave and long wave exhaust plume observed from aircraft tail exhibited symmetrical distribution. The greatest radiation intensity and area of the former were 4.6 and 2.1 times as those of the latter respectively. The greatest radiation intensity, plume length and area of mid-wave infrared plume observed from the side of aircraft were 2.2, 3.8 and 5.7 times as those of long wave infrared plume respectively. The advantages of the former were more obvious. In addition, because of the influence of high temperature heating of plume, the temperature of the air around plume rises significantly. Its radiation intensity was higher than that of other background. The measurement results obtained were of referential value to the simulation and calculation of infrared radiation characteristics of aircraft plume.