Stellar evolution simulation method based on dynamic convection model and adaptive grid
Leyi Ye
School of Science, The Hong Kong University of Science and Technology
DOI: https://doi.org/10.59429/esta.v12i4.12674
Keywords: stellar evolution; dynamic convection; adaptive mesh refinement
Abstract
This study proposes a new method for simulating stellar evolution based on a dynamical convection model (DCM) and adaptive mesh refinement (AMR). This method overcomes the limitations of conventional algorithms through three key innovations: First, a nuclear burning-driven term is innovatively introduced into the dynamic convection model, directly coupling the nuclear reaction energy with the turbulent kinetic energy, addressing the traditional model's neglect of combustion-convection interactions. Second, a rotational modulation term and a chemical composition term are used to achieve a self-consistent description of rotation, chemical gradients, and turbulence for the first time. Third, an intelligent adaptive mesh refinement criterion is developed, which, through the synergistic effect of the gradient compression factor and the nuclear burning priority term, improves the resolution of key regions such as the burning shell. Numerical experiments demonstrate that the new method significantly improves simulation accuracy: RMSE errors were reduced in eight of ten comparisons. Furthermore, mixing efficiency was significantly improved, increasing by 12.5%, 40%, and 20% for low-mass, medium-mass, and high-mass stars respectively. This method provides a new tool for accurately simulating the evolution of stellar interior structures and predicting element abundance distributions.
References
[1] Dotter A, Chaboyer B, Jevremović D, et al. The Dartmouth stellar evolution database[J]. The Astrophysical Journal Supplement Series, 2008, 178(1): 89.
[2] Schwarzschild M. Structure and evolution of stars[M]. Princeton University Press, 2015.
[3] Kippenhahn R, Weigert A, Weiss A. Stellar structure and evolution[M]. Berlin: Springer-verlag, 1990.
[4] Wagoner R V. Synthesis of the elements within objects exploding from very high temperatures[J]. Astrophysical Journal Supplement, vol. 18, p. 247 (1969), 1969, 18: 247.
[5] Arnett D, Bazan G. Nucleosynthesis in stars: Recent developments[J]. Science, 1997, 276(5317): 1359-1362.
[6] Renzini A. Some embarrassments in current treatments of convective overshooting[J]. Astronomy and Astrophysics (ISSN 0004-6361), vol. 188, no. 1, Dec. 1987, p. 49-54., 1987, 188: 49-54.
[7] Herwig F. The evolution of AGB stars with convective overshoot[J]. arXiv preprint astro-ph/0007139, 2000.
[8] Pols O R, Schröder K P, Hurley J R, et al. Stellar evolution models for Z= 0.0001 to 0.03[J]. Monthly Notices of the Royal Astronomical Society, 1998, 298(2): 525-536.
[9] Lamers H J, Levesque E M. Understanding Stellar Evolution[M]. IoP Publishing, 2017.
[10] Iben I. Stellar evolution physics[M]. Cambridge University Press, 2013.
[11] Eyer L, Mowlavi N. Variable stars across the observational HR diagram[C]//Journal of Physics: Conference Series. IOP Publishing, 2008, 118(1): 012010.
[12] Eggleton P P. Composition changes during stellar evolution[J]. Monthly Notices of the Royal Astronomical Society, 1972, 156(3): 361-376.