Abstract
In this paper, we describe a new hydrodynamics code for one- and two-dimensional (1D and 2D) astrophysical simulations, BETHE-hydro, that uses time-dependent, arbitrary, unstructured grids. The core of the hydrodynamics algorithm is an arbitrary Lagrangian-Eulerian (ALE) approach, in which the gradient and divergence operators are made compatible using the support-operator method. We present 1D and 2D gravity solvers that are finite differenced using the support-operator technique, and the resulting system of linear equations are solved using the tridiagonal method for 1D simulations and an iterative multigrid-preconditioned conjugate-gradient method for 2D simulations. Rotational terms are included for 2D calculations using cylindrical coordinates. We document an incompatibility between a subcell pressure algorithm to suppress hourglass motions, and the subcell remapping algorithm and present a modified subcell pressure scheme that avoids this problem. Strengths of this code include a straightforward structure, enabling simple inclusion of additional physics packages, the ability to use a general equation of state, and most importantly, the ability to solve self-gravitating hydrodynamic flows on time-dependent, arbitrary grids. In what follows, we describe in detail the numerical techniques employed and,with a large suite of tests, demonstrate that BETHE-hydro finds accurate solutions with second-order convergence.
Original language | English (US) |
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Pages (from-to) | 209-241 |
Number of pages | 33 |
Journal | Astrophysical Journal, Supplement Series |
Volume | 179 |
Issue number | 1 |
DOIs | |
State | Published - Nov 2008 |
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science
Keywords
- Hydrodynamics
- Instabilities
- Methods: numerical
- Shock waves
- Supernovae: general