master thesis - Astrophysik Kiel - Christian-Albrechts-Universität zu ...

Abstract
Accretion disks of black holes and protostars often show concise structures, of which
the origins remain yet unknown. Their evolution can be disturbed significantly by an
embedded or passing-by gravitating object, which induces spiral and ring structures. In
this thesis we discuss satellite-disk interactions and their resulting structures as well as
hydrodynamic simulations of planet-disk interactions using the two-dimensional hydrodynamic
software FOSITE.
Simulations of gravitationally disturbed accretion disks are very sensitive to their accurate
numerical description, in particular to their conservation of angular momentum
in a rotating frame of reference. To achieve exact conservation of angular momentum
in the inertial frame of reference, we develop Navier-Stokes equations, which transport
inertial angular momentum rather than the azimuthal momentum. This requires a newly
developed modification of the numerical scheme implemented in FOSITE.
We verify the Navier-Stokes equations with inertial angular momentum transport including
a new variant of the isentropic vortex test, which considers the local verticalisothermal
equation of state approximation. The correct functionality of planet-disk interactions
utilizing the modified version of FOSITE is discussed in detail and compared
to high-resolution simulation. We show that our results are consistent with the vast majority
of other hydrodynamic codes without sacrificing the versability of FOSITE, which
surpasses all other codes by a wide margin.