3D hydrodynamic simulations of massive main-sequence stars. III. The effect of radiation pressure and diffusion leading to a 1D equilibrium model

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Mao, Huaqing, Woodward, Paul, Herwig, Falk, Denissenkov, Pavel A., Blouin, Simon, Thompson, William, McDermott, Benjamin
Formato: Preprint
Publicado: 2023
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866910562037792768
author Mao, Huaqing
Woodward, Paul
Herwig, Falk
Denissenkov, Pavel A.
Blouin, Simon
Thompson, William
McDermott, Benjamin
author_facet Mao, Huaqing
Woodward, Paul
Herwig, Falk
Denissenkov, Pavel A.
Blouin, Simon
Thompson, William
McDermott, Benjamin
contents We present 3-D hydrodynamical simulations of core convection with a stably stratified envelope of a \unit{25}{\Msun} star in the early phase of the main-sequence. We use the explicit gas-dynamics code \code{PPMstar} which tracks two fluids and includes radiation pressure and radiative diffusion. Multiple series of simulations with different luminosities and radiative thermal conductivities are presented. The entrainment rate at the convective boundary, internal gravity waves in and above the boundary region, and the approach to dynamical equilibrium shortly after a few convective turnovers are investigated. We perform very long simulations on $896^3$ grids accelerated by luminosity boost factors $1000$, $3162$ and $10000$. In these simulations the growing penetrative convection reduces the initially unrealistically large entrainment. This reduction is enabled by a spatial separation that develops between the entropy gradient and the composition gradient. The convective boundary moves outward much more slowly at the end of these simulations. Finally, we present a 1-D method to predict the extent and character of penetrative convection beyond the Schwarzschild bounxdary. The 1-D model is based on a spherically-averaged reduced entropy equation that takes the turbulent dissipation as input from the 3-D hydrodynamic simulation and takes buoyancy and all other energy sources and sinks into account. This 1-D method is intended to be ultimately deployed in 1-D stellar evolution calculations and is based on the properties of penetrative convection in our simulations carried forward through the local thermal timescale.
format Preprint
id arxiv_https___arxiv_org_abs_2304_10470
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle 3D hydrodynamic simulations of massive main-sequence stars. III. The effect of radiation pressure and diffusion leading to a 1D equilibrium model
Mao, Huaqing
Woodward, Paul
Herwig, Falk
Denissenkov, Pavel A.
Blouin, Simon
Thompson, William
McDermott, Benjamin
Solar and Stellar Astrophysics
We present 3-D hydrodynamical simulations of core convection with a stably stratified envelope of a \unit{25}{\Msun} star in the early phase of the main-sequence. We use the explicit gas-dynamics code \code{PPMstar} which tracks two fluids and includes radiation pressure and radiative diffusion. Multiple series of simulations with different luminosities and radiative thermal conductivities are presented. The entrainment rate at the convective boundary, internal gravity waves in and above the boundary region, and the approach to dynamical equilibrium shortly after a few convective turnovers are investigated. We perform very long simulations on $896^3$ grids accelerated by luminosity boost factors $1000$, $3162$ and $10000$. In these simulations the growing penetrative convection reduces the initially unrealistically large entrainment. This reduction is enabled by a spatial separation that develops between the entropy gradient and the composition gradient. The convective boundary moves outward much more slowly at the end of these simulations. Finally, we present a 1-D method to predict the extent and character of penetrative convection beyond the Schwarzschild bounxdary. The 1-D model is based on a spherically-averaged reduced entropy equation that takes the turbulent dissipation as input from the 3-D hydrodynamic simulation and takes buoyancy and all other energy sources and sinks into account. This 1-D method is intended to be ultimately deployed in 1-D stellar evolution calculations and is based on the properties of penetrative convection in our simulations carried forward through the local thermal timescale.
title 3D hydrodynamic simulations of massive main-sequence stars. III. The effect of radiation pressure and diffusion leading to a 1D equilibrium model
topic Solar and Stellar Astrophysics
url https://arxiv.org/abs/2304.10470