  Context. Structuring in the solar atmosphere, in the form of inhomogeneities
transverse to the magnetic field, is believed to play a vital role in wave
propagation, conversion, and absorption. Aims. We investigated the effect of
transverse structuring on the processes of mode conversion and wave energy flux
absorption using a 3D ideal magnetohydrodynamic simulation featuring an
expanding coronal loop in a gravitationally stratified atmosphere. Methods.
Multiple wave drivers were modelled. The location of the driver at the
photospheric base was allowed to vary so that we could study how the driven
waves interact with the transverse structuring, provided by the magnetic field,
as well as with the vertical structuring due to gravity. Results. We find that
the transverse structuring acts as a conduit for Alfv\'en wave energy flux
through the transition region and into the solar corona. Moreover, in regions
of strong transverse gradients, the reflection of Alfv\'en waves at the
transition region is greatly reduced, supporting results from recent studies.
Finally, we investigated the efficiency of the loop structuring at absorbing
energy flux from externally driven waves and find that the loop is extremely
effective at channelling wave energy flux to the loop apex in the corona; in
some cases, it can absorb over a third of the externally driven wave energy
flux. Conclusions. These results may have important consequences in the context
of decayless loop oscillations as they suggest that the oscillations are driven
by acoustic waves outside of the existing loop structure.
