Abstract
The efficacy of immersed boundary (IB) methods with adaptive mesh refinement (AMR) techniques is assessed in the context of atmospheric entry applications, including effects of chemical nonequilibrium (CNE) and gas–surface interactions (GSI). We scrutinize a conservative cut-cell IB method and two non-conservative IB methods, comparing their results with analytical solutions, data from the literature, and results obtained with a reference solver that operates on body-fitted grids. All solvers employ the same external thermochemistry library, ensuring that all observed differences can be attributed solely to differences in the underlying numerical methodologies. We present results for eight benchmark cases. Four verification cases verify the implementation of chemistry, transport properties, catalytic boundary conditions, and shock capturing. Four validation cases encompass blunt geometries with adiabatic and isothermal, as well as inert, catalytic and ablative boundary conditions. Overall, the results obtained with the IB solvers are in very good agreement with the reference data. Discrepancies arise in cases with large temperature or concentration gradients at the wall, and these are linked to conservation errors inherent to ghost-cell and interpolation-based IB methods. Only a strictly conservative cut-cell IB method is on par with body-fitted grid methods.
Original language | English |
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Article number | 106134 |
Journal | Computers and Fluids |
Volume | 270 |
DOIs | |
Publication status | Published - 2024 |
Funding
We extend our sincere appreciation to Prof. Giuseppe Pascazio, Dr. Francesco Bonelli, and Dr. Davide Ninni from Politecnico di Bari for their valuable collaboration, insightful discussions regarding methods and results, and their comments on the manuscript. From TU Delft, we thank Prof. Georg Eitelberg for his insights concerning the experiments carried out at DLR and Dr. Ferdinand Schrijer for his critical feedback on the manuscript. We acknowledge the Delft High Performance Computing Center (DHPC) for providing access to DelftBlue, the SURF Cooperative (www.surf.nl) for their services, and the Dutch Research Council (NWO) for providing access to Snellius.Keywords
- Ablation
- Atmospheric entry
- Gas–surface interaction
- Hypersonic flow
- Immersed boundary method
- Mass conservation