首先介绍固体发动机尾焰中钾原子的来源及其在尾焰中的辐射机理,并基于原子谱线理论对尾焰钾共振双线的光谱线型特征进行分析。然后,采用理想模型及半经验公式法对尾焰流场分布进行数值模拟,通过尾焰的流场参数使用C-G近似法数值计算尾焰钾共振双线的辐射特性。最后,利用大气辐射传输模型计算尾焰中钾共振双线辐射信号经过大气传输后到达探测系统的光谱特征。结果表明,该方法能有效地仿真计算尾焰近红外钾线高光谱精细结构。仿真结果亦表明钾共振双线光谱信号能有效通过大气传输,可作为尾焰探测识别的依据。
Firstly,the source of potassium atoms in solid rocket engine exhaust plume and its radiation mechanism were introduced, and the spectrum of the potassium resonance doublet shape was analyzed based on the theory of atomic spectra.Secondly,the numerical simulation of the plume flow field distribution was carried out with the ideal jet model and the semi-empirical formula.The radiation spectral characteristics of potassium resonance doublet shape from rocket plume were calculated by using the C-G approximation method.Finally,the spectral characteristics of potassium resonance doublet shape signal in the wake of the plume were calculated by using the atmospheric radiative transfer model.The results demonstrate that this method can effectively simulate the fine structure of the NIR spectrum of exhaust plume.The simulation results also show that the signal energy of potassium resonance doublet spectrum can be effectively transmitted through atmosphere,which can be used as the basis for the detection and identification of exhaust plume.