  In the present study we investigate magnetic reconnection in twisted magnetic
fluxtubes with different initial configurations. In all considered cases,
energy release is triggered by the ideal kink instability, which is itself the
result of applying footpoint rotation to an initially potential field. The main
goal of this work is to establish the influence of the field topology and
various thermodynamic effects on the energy release process. Specifically, we
investigate convergence of the magnetic field at the loop footpoints,
atmospheric stratification, as well as thermal conduction. In all cases, the
application of vortical driving at the footpoints of an initally potential
field leads to an internal kink instability. With the exception of the curved
loop with high footpoint convergence, the global geometry of the loop change
little during the simulation. Footpoint convergence, curvature and atmospheric
structure clearly influences the rapidity with which a loop achieves
instability as well as the size of the subsequent energy release. Footpoint
convergence has a stabilising influence and thus the loop requires more energy
for instability, which means that the subsequent relaxation has a larger
heating effect. Large-scale curvature has the opposite result: less energy is
needed for instability and so the amount of energy released from the field is
reduced. Introducing a stratified atmosphere gives rise to decaying wave
phenomena during the driving phase, and also results in a loop that is less
stable.
