火箭发动机喷焰涉及复杂的流动、复燃和辐射效应, 并对喷焰辐射的光学探测跟踪有着重要的影响。以固体火箭发动机为研究对象, 建立喷焰化学反应复燃数值模拟方法和视线光辐射传输数值计算方法, 对不同飞行条件下的喷焰流动、辐射特性进行计算分析, 重点考察复燃效应对不同高度喷焰辐射特性的影响。研究结果表明: 复燃效应引起喷焰温升可达到1 000 K, 并使得喷焰谱带辐射强度有10倍以上的增强; 对于不同谱带辐射强度会随高度先升后降, 最大的高度在20~30 km, 短波2.7 μm波段有约17倍的辐射增强, 中波4.3 μm波段约有16倍增强, 可见复燃引起辐射增强作用H2O分子的贡献大于CO2分子的贡献。研究结果可为进一步的理论研究和工程应用提供参考。

Exhaust plumes of solid rocket motors involve complex flow state, afterburning and radiation effects, which have an important role in the operations of detecting, indentifying, and tracking. To investigate the characteristics of afterburning and radiation effects under different flight conditions, the computational fluid dynamics method and the finite-rate ratio model were used to simulate the flow properties with chemical reactions, and line of sight method was utilized to solve the radiation transmission equations. The influence of afterburning effect on the radiation characteristics of different heights was analyzed. The results show that the afterburning effect can cause the flame temperature rise to 1 000 K, and increase the radiation brightness of the flame band more than 10 times. For different bands, the radiation brightness rises and then decreases along with the height. The maximal position is 20-30 km, with about 17 times radiation enhancement in the short wave 2.7 μm waveband and about 16 times in the 4.3 μm mid wave waveband. It can be seen that the contribution of the H2O molecule caused by the afterburning is greater than that of the CO2 molecule. Theses can provide reference for further theoretical research and engineering application.