The Athena++ Adaptive Mesh Refinement Framework: Multigrid Solvers for Self-gravity
Abstract
We describe the implementation of multigrid solvers in the Athena++ adaptive mesh refinement (AMR) framework and their application to the solution of the Poisson equation for self-gravity. The new solvers are built on top of the AMR hierarchy and TaskList framework of Athena++ for efficient parallelization. We adopt a conservative formulation for the Laplacian operator that avoids artificial accelerations at level boundaries. Periodic, fixed, and zero-gradient boundary conditions are implemented, as well as open boundary conditions based on a multipole expansion. Hybrid parallelization using both Message Passing Interface and OpenMP is adopted, and we present results of tests demonstrating the accuracy and scaling of the methods. On a uniform grid, we show that multigrid significantly outperforms methods based on fast Fourier transforms, and requires only a small fraction of the computing time required by the (highly optimized) magnetohydrodynamic solver in Athena++. As a demonstration of the capabilities of the methods, we present the results of a test calculation of magnetized protostellar collapse on an adaptive mesh.
- Publication:
-
The Astrophysical Journal Supplement Series
- Pub Date:
- May 2023
- DOI:
- 10.3847/1538-4365/acc2c0
- arXiv:
- arXiv:2302.13903
- Bibcode:
- 2023ApJS..266....7T
- Keywords:
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- Astronomical simulations;
- Hydrodynamical simulations;
- Magnetohydrodynamical simulations;
- Gravitation;
- Star formation;
- 1857;
- 767;
- 1966;
- 661;
- 1569;
- Astrophysics - Instrumentation and Methods for Astrophysics
- E-Print:
- 28 pages, 13 figures, submitted to AAS Journals