Planet-disc interactions with Discontinuous Galerkin Methods using GPUs

• Published in: arXiv.org 2018-05
• Main Authors: Velasco-Romero, David A, Maria Han Veiga, Teyssier, Romain, Masset, Frédéric S
• Format: Article
• Language: English
• Subjects: Galerkin method; Time dependence; Viscosity
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1805.01443

We present a two-dimensional Cartesian code based on high order discontinuous Galerkin methods, implemented to run in parallel over multiple GPUs. A simple planet-disc setup is used to compare the behaviour of our code against the behaviour found using the FARGO3D code with a polar mesh. We make use of the time dependence of the torque exerted by the disc on the planet as a mean to quantify the numerical viscosity of the code. We find that the numerical viscosity of the Keplerian flow can be as low as a few \(10^{-8}r^2\Omega\), \(r\) and \(\Omega\) being respectively the local orbital radius and frequency, for fifth order schemes and resolution of \(\sim 10^{-2}r\). Although for a single disc problem a solution of low numerical viscosity can be obtained at lower computational cost with FARGO3D (which is nearly an order of magnitude faster than a fifth order method), discontinuous Galerkin methods appear promising to obtain solutions of low numerical viscosity in more complex situations where the flow cannot be captured on a polar or spherical mesh concentric with the disc.