窄谱带模型数值研究高温喷流动态红外特性

对高温超声速喷流流场的动态红外辐射特性进行研究.采用窄谱带模型结合光谱数据库及Mie散射理论建立求解非灰吸收、发射、散射性介质红外辐射传输计算模型.数值模拟了某高温喷流2～5μm光谱红外特性,获得了不同飞行高度时高温喷流的红外仿真热像、光谱、波段及总辐射强度仿真数据.比较结果表明:高温喷流在2～5μm光谱呈明显双峰特性;动态飞行时喷流红外光谱选择性是相类似的,光谱总辐射强度随高度增加先增大后减弱;低空时2～3μm波段辐射强度大于4～5μm波段辐射强度,而随着高度的增加,4～5μm波段辐射强度将大于2～3μm波段辐射强度。

Numerical study on dynamic infrared properties of high temperature jetflow using narrow-band model

Dynamic infrared properties of high temperature hypersonic jetflow have been investigated.A numerical method was developed to solve the radiative heat transfer for non-gray absorbing,emitting and scattering medium by using the narrow-band model combined with molecular spectral access and the Mie scattering theory.The 2-5 microwave infrared properties of a high temperature jetflow including infrared images,spectral radiances,inband radiances and apparent source intensities were simulated at different altitudes.The results show that there are two distinct peak values in the jetflow spectra,and the spectral selection are similar at various altitudes.When the flight altitude begins increasing with ignition,the infrared spectral radiances increase until a certain altitude,and then get lower.At low altitude,the 2-3 microwave inband radiance are larger than the 4-5 microwave inband radiance,and the 4-5 inband radiance will become bigger than the 2-3 microwave inband radiance when the altitude increases.