  Oscillations are abundant in the solar corona. Coronal loop oscillations are
typically studied using highly idealised models of magnetic flux tubes. In
order to improve our understanding of coronal oscillations, it is necessary to
consider the effect of realistic magnetic field topology and density
structuring. We analyse the damping of coronal oscillations using a
self-consistent 3D radiation-MHD simulation of the solar atmosphere spanning
from the convection zone into the corona, the associated oscillation
dissipation and heating, and finally the physical processes responsible for the
damping and dissipation. The simulated corona formed in such a model does not
depend on any prior assumptions about the shape of the coronal loops. We find
that the bundle of magnetic loops shows damped transverse oscillations in
response to perturbations in two separate instances with oscillation periods of
177 s and 191 s, velocity amplitudes of 10 km/s and 16 km/s and damping times
of 176 s and 198 s, respectively. The coronal oscillations lead to the
development of velocity shear in the simulated corona resulting in the
formation of vortices seen in the velocity field caused by the Kelvin-Helmholtz
instability, contributing to the damping and dissipation of the transverse
oscillations. The oscillation parameters and evolution observed are in line
with the values typically seen in observations of coronal loop oscillations.
The dynamic evolution of the coronal loop bundle suggests the models of
monolithic and static coronal loops with constant lengths might need to be
re-evaluated by relaxing the assumption of highly idealised waveguides.
