Conservative Initial Mapping For Multidimensional Simulations of Stellar Explosions

TL;DR

This paper presents a new numerical scheme for accurately mapping 1D stellar profiles onto multidimensional grids in hydrodynamics simulations, ensuring conservation of physical quantities like energy and mass.

Contribution

The authors introduce a conservation-preserving mapping scheme for stellar data transfer from 1D to multidimensional grids, validated with realistic stellar profiles in a hydrodynamics code.

Findings

Conservation laws are maintained after mapping at all resolutions.

Important stellar profile features are accurately reproduced.

The scheme reduces numerical artifacts in multidimensional simulations.

Abstract

Mapping one-dimensional stellar profiles onto multidimensional grids as initial conditions for hydrodynamics calculations can lead to numerical artifacts, one of the most severe of which is the violation of conservation laws for physical quantities such as energy and mass. Here we introduce a numerical scheme for mapping one-dimensional spherically-symmetric data onto multidimensional meshes so that these physical quantities are conserved. We validate our scheme by porting a realistic 1D Lagrangian stellar profile to the new multidimensional Eulerian hydro code CASTRO. Our results show that all important features in the profiles are reproduced on the new grid and that conservation laws are enforced at all resolutions after mapping.