High-speed flow problems of practical interest require a solution of nonequilibrium aerothermochemistry to accurately predict important flow phenomena, including surface heat transfer and stresses. The complex coupling of nonequilibrium effects on the aerothermal load remains a challenging aspect of hypersonic flow modeling. As a majority of these flow problems are in the continuum regime, computational fluid dynamics (CFD) is a useful tool for modeling nonequilibrium flows. However, there are a limited number of CFD solvers with nonequilibrium flow modeling capabilities that are highly scalable on parallel architectures and can handle complex geometries. This work demonstrates that a commercial general purpose CFD solver can be effectively modified to include high-fidelity nonequilibrium aerothermochemistry and transport models. The paper presents modifications of a general purpose CFD solver, ANSYS Fluent, using the user defined functions to model salient aspects of nonequilibrium flow in air with a five-species reacting mixture: ${\mathrm{N}}_2$, ${\mathrm{O}}_2$, NO, N, and O. The modifications to the solver include Gupta–Yos high temperature mixing laws and Park’s two-temperature nonequilibrium chemistry models. The developed solver was verified for several benchmark nonequilibrium flow problems and compared with the available experimental data and other nonequilibrium flow simulations. The work establishes future possibilities for coupled aerothermal and electromagnetic simulations in thermochemical nonequilibrium.

实际感兴趣的高速流动问题需要非平衡空气热化学的解决方案，以准确预测重要的流动现象，包括表面传热和应力。非平衡效应对气动热载荷的复杂耦合仍然是高超声速流动建模的一个具有挑战性的方面。由于这些流动问题中的大多数处于连续介质状态，因此计算流体动力学 (CFD) 是对非平衡流动进行建模的有用工具。但是，具有非平衡流建模功能的 CFD 求解器数量有限，这些求解器在并行架构上具有高度可扩展性，并且可以处理复杂的几何形状。这项工作表明，可以有效地修改商业通用 CFD 求解器，以包括高保真非平衡空气热化学和传输模型。${\mathrm{N}}_2$, ${\mathrm{哦}}_2$、NO、N 和 O。对求解器的修改包括 Gupta-Yos 高温混合定律和 Park 的双温度非平衡化学模型。开发的求解器针对几个基准非平衡流动问题进行了验证，并与可用的实验数据和其他非平衡流动模拟进行了比较。这项工作为热化学非平衡中的气热和电磁耦合模拟建立了未来的可能性。