Radiation heat transfer plays a dominant role in high-temperature flow field. Rapid and reliable calculation of spectral radiation properties is beneficial for thermal analysis and detection of radiation target. In this paper, a multiscale-band k-distribution model is proposed for the study of radiation properties in high-temperature gases. The accurate absorption coefficients are firstly calculated using the line-by-line model. The slope of the accurate absorption coefficient line and its slope threshold are then extracted and analyzed, which act as a basis to divide the absorption coefficient line into multiple segments. For different segments, different bandwidths are chosen for the corresponding band k-distribution model. In the model, the 7-point Gauss–Lobatto method is employed to obtain the optimized absorption coefficients. These optimized absorption coefficients formed the absorption coefficient database. The radiation intensities of gases are finally calculated and analyzed based on the optimized database. Experimental results suggest that the multiscale-band k-distribution model can improve the efficiency up to 35% compared with the widely used narrow-band k-distribution model. Simultaneously, the relative calculation error is less than 5% compared with the most accurate line-by-line model.

中文翻译：

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高温气体中分子的多尺度带 K 分布模型

辐射传热在高温流场中起主导作用。快速可靠地计算光谱辐射特性有利于辐射目标的热分析和检测。本文提出了一种多尺度波段k分布模型，用于研究高温气体中的辐射特性。首先使用逐行模型计算准确的吸收系数。然后提取并分析准确吸收系数线的斜率及其斜率阈值，作为将吸收系数线分成多段的基础。对于不同的段，为相应的频段k-选择不同的带宽分销模式。在模型中，采用 7 点 Gauss-Lobatto 方法获得优化的吸收系数。这些优化后的吸收系数形成了吸收系数数据库。最后基于优化后的数据库计算分析气体的辐射强度。实验结果表明，与广泛使用的窄带k分布模型相比，多尺度带k分布模型可以将效率提高35% 。同时，与最精确的逐行模型相比，相对计算误差小于5%。