低空多喷管发动机喷焰红外特性研究

对多喷管火箭发动机低空尾焰的红外辐射特性进行了研究.基于热流法建立了喷焰红外传输计算模型,数值模拟了四喷管发动机尾流场2～5 μm光谱的红外特性.获得了光谱、波段辐射强度仿真数据及红外仿真热像,并与单喷管喷焰的红外特性进行了比较.考察了不同的喷管间距、探测方向、飞行高度对喷焰表观辐射强度的影响.结果表明,多喷管尾喷焰红外辐射光谱选择性与单喷管相似,但光谱峰值无线性关系;对于低空四喷管发动机尾喷焰,红外特性随喷管间距增加有所增强,随飞行高度增加,喷焰红外辐射强度提高.

Study on infrared properties of low altitude multi-nozzle engine exhaust plume

Infrared properties of multi-nozzle rocket exhaust plume at low altitude were investigated. The heat flux method was adopted to solve the radiative heat transfer for exhaust plume. The 2～5 μm microwave infrared properties of a four nozzles engine exhaust plume including spectral radiances, inband radiances and infrared images were simulated at different altitudes, and compared with the infrared properties of the rocket with single nozzle. The influences of nozzle spacing, detect angle and flight altitude to plume infrared signatures were analyzed. The results show that the spectral radiative selectivity of multi-nozzle exhaust plume is similar to the single nozzle plume,while there is not linear relationship between the two peak values. For low altitude four nozzle engine plume, the infrared properties are enhanced when the nozzle spacing increases,and the radiation intensities increase when the flight height increases.