A Multi-Solver Approach for Studying Ablation and Radiation Interactions in Hypersonics Flows

Accurate prediction of aerothermal behavior in high-speed atmospheric entry is a multiphysics coupled problem that spans on a wide range of temporal and spatial scales, which has limited the development of a unique and computationally efficient numerical model that able to capture accurately all the physical processes at play. In order to alleviate this restriction, this work proposes a multi-solver approach to solve simultaneously the hypersonic flow, material ablation and induced radiative transfer for atmospheric entry applications. The developed strategy consists in coupling physics-specific solvers that have been developed and validated independently in their own scope of relevance. The coupling capabilities are enable through a data exchanged library that allows communication of relevant physical variables both on surface and volume of interest. Advantages of multi-solver approach as compared to a monolithic model are highlighted by the flexibility of the data exchange strategy chosen in this work. The resulting numerical framework is demonstrated to study ablation of carbon material at high Mach number. The multiple interactions among the solvers are considered, and the relevance of such a coupled approach is highlighted by investigating the influence of material ablation on radiative response in detail. It was found that at the high Mach number influence of the radiation coupling is more critical than the material response on the radiative heat flux prediction. Also, the ablative product absorbs the radiative heat in the vacuum ultraviolet, whereas emits in the ultraviolet, especially via CN Violet and Red systems in the simulated condition.