A well-balanced scheme for the simulation tool-kit A-MaZe: implementation, tests, and first applications to stellar structure
| Autor: | Popov, M. V., Walder, R., Folini, D., Goffrey, T., Baraffe, I., Constantino, T., Geroux, C., Pratt, J., Viallet, M. |
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| Rok vydání: | 2019 |
| Předmět: | |
| Zdroj: | A&A 630, A129 (2019) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1051/0004-6361/201834180 |
| Popis: | Characterizing stellar convection in multiple dimensions is a topic at the forefront of stellar astrophysics. Numerical simulations are an essential tool for this task. We present an extension of the existing numerical tool-kit A-MaZe that enables such simulations of stratified flows in a gravitational field. The finite-volume based, cell-centered, and time-explicit hydrodynamics solver of A-MaZe was extended such that the scheme is now well-balanced in both momentum and energy. The algorithm maintains an initially static balance between gravity and pressure to machine precision. Quasi-stationary convection in slab-geometry preserves gas energy (internal plus kinetic) on average despite strong local up- and down-drafts. By contrast, a more standard numerical scheme is demonstrated to result in substantial gains of energy within a short time on purely numerical grounds. The test is further used to point out the role of dimensionality, viscosity, and Rayleigh number for compressible convection. Applications to a young sun in 2D and 3D, covering a part of the inner radiative zone as well as the outer convective zone, demonstrate that the scheme meets its initial design goal. Comparison with results obtained for a physically identical setup with a time-implicit code show qualitative agreement. Comment: 12 pages, 8 figures, accepted 30/08/2019 for publication by Astronomy & Astrophysics |
| Databáze: | arXiv |
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