Appropriate solid-body models as initial conditions for SPH-based numerical collision experiments

Autor(en)

Christoph Burger, Thomas Maindl, Rudolf Dvorak, Christoph Schäfer, Roland Speith

Abstrakt

Providing the simulation algorithm with suitable initial conditions is a crucial first step in almost all numerical computations, except for the most trivial cases. Even the most sophisticated simulation program will not produce meaningful results if not started with an appropriate initial configuration, satisfying demands like isotropy, a low level of noise and physical accuracy. Some of these requirements are unique to Smoothed Particle Hydrodynamics (SPH) - the numerical method considered here - others are of fundamental relevance, independent of the chosen numerical technique. The main focus of this work lies on considerations concerning initial conditions for subsequent SPH simulation runs. The geometrical arrangement of an initial SPH particle setup is discussed, particularly w.r.t. regular lattice configurations and associated symmetry effects. In order to avoid unphysical behavior the initial particle configuration has to be in a relaxed (i.e. equilibrated) state where necessary. This is of particular importance for simulations of giant collisions, where the involved bodies naturally exhibit a hydrostatic internal structure. Beyond the common numerical procedure, a semi-analytical approach for relaxation is introduced and validated, practically eliminating the need for spending significant amounts of valuable computing time solely for the production of a relaxed initial state in a lot of situations. Finally the basic relevance of relaxation itself is studied, focusing on collision simulations in different mass ranges important in the context of planet formation and the transport of water.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

Eberhard Karls Universität Tübingen

Seiten

67

Anzahl der Seiten

1

Publikationsdatum

02-2016

ÖFOS 2012

103003 Astronomie, 103004 Astrophysik

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/2bc623b7-6071-4587-860e-1604c36dc31e