复燃对液体火箭尾焰红外辐射特性的影响

为了定量研究复燃对液体火箭尾焰红外辐射特性的影响,建立了一个可以计算液体火箭尾焰复燃流场和红外辐射特性的模型.首先,使用FLUENT软件计算液体火箭尾焰复燃流场,其中尾焰中的复燃反应使用有限速率化学反应模型计算;然后,使用基于HITEMP数据库的窄带模型计算尾焰内气体的辐射参量;最后,使用有限体积法求解尾焰中的辐射传输方程.通过比较该模型计算的Titan IIIB尾焰光谱辐射强度与(美国)国家航空航天局公布结果的一致性,证明了该模型的正确性.最后,利用该模型计算了复燃对某液体火箭尾焰光谱和波段红外辐射强度的影响,结果表明,复燃反应可以显著增加尾焰红外光谱辐射强度,在2.5~3.0 μm和4.2~4.7 μm两个主要辐射波段平均辐射强度的增加比例分别达到了30.8%和28.3%,所以,在计算液体火箭尾焰准确的红外辐射特性时,需要考虑复燃的影响.

Influence of Afterburning on Infrared Radiation of Liquid Rocket Exhaust Plume

In order to study the influence of afterburning on the infrared radiation of a liquid rocket exhaust plume, a model was founded which could calculate afterburning flow field and infrared radiation of a liquid rocket exhaust plume. The FLUENT was used to calculate the afterburning flow field of a liquid rocket exhaust plume, the finite rate chemistry reaction model was adopted to calculate the afterburning reaction. Then, a narrow band model based on the HITEMP data base was employed to calculate the radiation parameters of plume gas. Lastly, the finite volume method was used to solve the radiation transfer equation. The feasibility of this model was testified by comparing the calculated spectral radiation intensity of the Titan IIIB exhaust plume and the result of (American) National Aeronautics and Space Administration. By means of this model, the influence of afterburning on the infrared radiation of a liquid rocket exhaust plume was calculated. The results show that, afterburning is able to increase the infrared spectral radiation greatly, and the average increase radio of the two domain radiation bands 2.5~3.0 μm and 4.2~4.7 μm achieve 30.8% and 28.3% respectively. Therefore, the afterburning should be taken into account when calculating the exact infrared radiation of a liquid rocket exhaust plume.