The GENGA Code: Gravitational Encounters in N-body simulations with GPU Acceleration
Institute for Computational Science, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
arXiv:1404.2324 [astro-ph.EP], (8 Apr 2014)
@article{2014arXiv1404.2324G,
author={Grimm}, S.~L. and {Stadel}, J.~G.},
title={"{The GENGA Code: Gravitational Encounters in N-body simulations with GPU Acceleration}"},
journal={ArXiv e-prints},
archivePrefix={"arXiv"},
eprint={1404.2324},
primaryClass={"astro-ph.EP"},
keywords={Astrophysics – Earth and Planetary Astrophysics},
year={2014},
month={apr},
adsurl={http://adsabs.harvard.edu/abs/2014arXiv1404.2324G},
adsnote={Provided by the SAO/NASA Astrophysics Data System}
}
We describe a GPU implementation of a hybrid symplectic N-body integrator, GENGA (Gravitational ENcounters with Gpu Acceleration), designed to integrate planet and planetesimal dynamics in the late stage of planet formation and stability analysis of planetary systems. GENGA is based on the integration scheme of the Mercury code (Chambers 1999), which handles close encounters with very good energy conservation. It uses mixed variable integration (Wisdom & Holman 1991) when the motion is a perturbed Kepler orbit and combines this with a direct N-body Bulirsch-Stoer method during close encounters. The GENGA code supports three simulation modes: Integration of up to 2048 massive bodies, integration with up to a million test particles, or parallel integration of a large number of individual planetary systems. GENGA is written in CUDA C and runs on all Nvidia GPUs with compute capability of at least 2.0. All operations are performed in parallel, including the close encounter detection and the grouping of independent close encounter pairs. Compared to Mercury, GENGA runs up to 30 times faster. GENGA is available as open source code from https://bitbucket.org/sigrimm/genga.
April 11, 2014 by hgpu
