Dynamics in a stellar convective layer and at its boundary: comparison of five 3D hydrodynamics codes

Our ability to predict the structure and evolution of stars is in part limited by complex, 3D hydrodynamic processes such as convective boundary mixing. Hydrodynamic simulations help us understand the dynamics of stellar convection and convective boundaries. However, the codes used to compute such s...

Full description

Saved in:
Bibliographic Details
Main Authors: Andrássy, Róbert (Author) , Higl, Johann (Author) , Mao, H. (Author) , Mocák, M. (Author) , Vlaykov, D. G. (Author) , Arnett, W. D. (Author) , Baraffe, I. (Author) , Campbell, S. W. (Author) , Constantino, T. (Author) , Edelmann, P. V. F. (Author) , Goffrey, T. (Author) , Guillet, T. (Author) , Herwig, F. (Author) , Hirschi, R. (Author) , Horst, Leonhard (Author) , Leidi, Giovanni (Author) , Meakin, C. (Author) , Pratt, J. (Author) , Rizzuti, F. (Author) , Röpke, Friedrich (Author) , Woodward, P. (Author)
Format: Article (Journal)
Language:English
Published: 28 March 2022
In: Astronomy and astrophysics
Year: 2022, Volume: 659, Pages: 1-19
ISSN:1432-0746
DOI:10.1051/0004-6361/202142557
Online Access:Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1051/0004-6361/202142557
Verlag, lizenzpflichtig, Volltext: https://www.aanda.org/articles/aa/abs/2022/03/aa42557-21/aa42557-21.html
Get full text
Author Notes:R. Andrassy, J. Higl, H. Mao, M. Mocák, D.G. Vlaykov, W.D. Arnett, I. Baraffe, S.W. Campbell, T. Constantino, P.V.F. Edelmann, T. Goffrey, T. Guillet, F. Herwig, R. Hirschi, L. Horst, G. Leidi, C. Meakin, J. Pratt, F. Rizzuti, F.K. Röpke, and P. Woodward
Description
Summary:Our ability to predict the structure and evolution of stars is in part limited by complex, 3D hydrodynamic processes such as convective boundary mixing. Hydrodynamic simulations help us understand the dynamics of stellar convection and convective boundaries. However, the codes used to compute such simulations are usually tested on extremely simple problems and the reliability and reproducibility of their predictions for turbulent flows is unclear. We define a test problem involving turbulent convection in a plane-parallel box, which leads to mass entrainment from, and internal-wave generation in, a stably stratified layer. We compare the outputs from the codes FLASH, MUSIC, PPMSTAR, PROMPI, and SLH, which have been widely employed to study hydrodynamic problems in stellar interiors. The convection is dominated by the largest scales that fit into the simulation box. All time-averaged profiles of velocity components, fluctuation amplitudes, and fluxes of enthalpy and kinetic energy are within ≲3<i>σ<i/> of the mean of all simulations on a given grid (128<sup>3<sup/> and 256<sup>3<sup/> grid cells), where <i>σ<i/> describes the statistical variation due to the flow’s time dependence. They also agree well with a 512<sup>3<sup/> reference run. The 128<sup>3<sup/> and 256<sup>3<sup/> simulations agree within 9% and 4%, respectively, on the total mass entrained into the convective layer. The entrainment rate appears to be set by the amount of energy that can be converted to work in our setup and details of the small-scale flows in the boundary layer seem to be largely irrelevant. Our results lend credence to hydrodynamic simulations of flows in stellar interiors. We provide in electronic form all outputs of our simulations as well as all information needed to reproduce or extend our study.
Item Description:Gesehen am 21.04.2022
Physical Description:Online Resource
ISSN:1432-0746
DOI:10.1051/0004-6361/202142557