Abstract The present work analyzes the stagnation-point radiative heating in the Fire II flight experiment by devising a collisional-radiative model with non-local absorption. In the stagnation-line flow-field calculations, a viscous shock layer method with a thermochemical nonequilibrium model is utilized. In the radiation calculations, a line-by-line method with the non-Boltzmann electronic populations is employed by adopting the quasi-steady state approach of the electronic master equation calculations. In constructing the electronic master equation, the best set of the electron and heavy-particle impact excitation rates is proposed to achieve better agreement with the measured radiative heating flight data. In the flow-radiation coupling procedure, the effect of the non-local absorption is modeled by devising an iterative process between the quasi-steady state electronic master equation and the radiative transfer equation calculations. Escape factors of the strongest atomic lines and the diatomic nitrogen vacuum ultraviolet systems with the non-local absorption effect are also proposed to more efficiently consider the non-local nature of the radiative transition. When compared with the experimental data from the Fire II trajectories, it is found that the present collisional-radiative model with the non-local absorption improves the ability to predict non-Boltzmann radiative heating.

中文翻译：

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非 Boltzmann 辐射模型 Fire II 的驻点加热

摘要 目前的工作通过设计具有非局部吸收的碰撞辐射模型来分析 Fire II 飞行实验中的驻点辐射加热。在滞流线流场计算中，使用了具有热化学非平衡模型的粘性冲击层方法。在辐射计算中，采用电子主方程计算的准稳态方法，采用非玻尔兹曼电子布居的逐行方法。在构建电子主方程时，提出了电子和重粒子撞击激发速率的最佳集合，以与测量的辐射加热飞行数据更好地吻合。在流动-辐射耦合过程中，通过设计准稳态电子主方程和辐射传递方程计算之间的迭代过程来模拟非局部吸收的影响。还提出了最强原子线的逃逸因子和具有非局域吸收效应的双原子氮真空紫外系统，以更有效地考虑辐射跃迁的非局域性质。与 Fire II 轨迹的实验数据相比，发现具有非局部吸收的当前碰撞辐射模型提高了预测非玻尔兹曼辐射加热的能力。还提出了最强原子线的逃逸因子和具有非局域吸收效应的双原子氮真空紫外系统，以更有效地考虑辐射跃迁的非局域性质。与 Fire II 轨迹的实验数据相比，发现具有非局部吸收的当前碰撞辐射模型提高了预测非玻尔兹曼辐射加热的能力。还提出了最强原子线的逃逸因子和具有非局域吸收效应的双原子氮真空紫外系统，以更有效地考虑辐射跃迁的非局域性质。与 Fire II 轨迹的实验数据相比，发现具有非局部吸收的当前碰撞辐射模型提高了预测非玻尔兹曼辐射加热的能力。