This study aims to investigate the influence of flight altitude on the plume radiation enhancement effect caused by afterburning. The infrared radiation simulation model consisting of the standard \(k - \varepsilon\) two-equation turbulence models, the finite velocity model, and the finite volume method (FVM) was established in this work. Based on the proposed model, the influence of afterburning on the flow field distribution and infrared radiation from sea level to the altitude of 50 km was analyzed. The results showed that the temperature and the contents of main radiant gases such as CO₂ and H₂O increase due to afterburning. Specifically, the increments were more significant at the altitude of 0–20 km than at the altitude of 30–50 km. Furthermore, the infrared radiation was enhanced as a result of afterburning, and the enhancement ratio decreased with the increase of altitude. When the altitude was below 20 km, the enhancement ratios of radiation intensity in wavebands of 2.5–2.9 μm and 4.1–4.5 μm were greater than 25%; when the altitude was higher than 40 km, the enhancement ratios were less than 10%. In particular, when the height was 50 km, the enhancement ratios of radiation intensity in wavebands of 2.5–2.9 μm and 4.1–4.5 μm were merely 6.09% and 3.99%, respectively. It can be concluded that the infrared radiation enhancement effect caused by afterburning is significant when the altitude is lower than 20 km, and will decrease with the increase of altitude when the altitude is higher than 20 km, which is mainly due to that oxygen concentration in the atmosphere decreases with the altitude.

这项研究旨在调查飞行高度对加力引起的羽流辐射增强效应的影响。建立了由标准\（k-\ varepsilon \）两方程湍流模型，有限速度模型和有限体积法（FVM）组成的红外辐射仿真模型。在此模型的基础上，分析了加力对流场分布和海平面至50 km的红外辐射的影响。结果表明，CO ₂和H ₂等主要辐射气体的温度和含量O因再燃而增加。具体而言，在0–20 km的高度处，增量比在30–50 km的高度处更显着。再燃后，红外辐射增强，增强比随高度的增加而降低。当海拔高度低于20 km时，2.5–2.9μm和4.1–4.5μm波段的辐射强度增强率大于25％；当海拔高于40 km时，增强率小于10％。特别是当高度为50 km时，2.5–2.9μm和4.1–4.5μm波段的辐射强度增强率分别仅为6.09％和3.99％。可以得出结论，海拔低于20 km时，由后燃引起的红外辐射增强效果显着，