  Aims - Investigate the effects of resistivity and viscosity on the onset and
growth of the Kelvin-Helmholtz instability (KHI) in an oscillating coronal
loop. Methods - We modelled a standing kink wave in a density-enhanced loop
with the three dimensional (3-D), resistive magnetohydrodynamics code, Lare3d.
We conducted a parameter study on the viscosity and resistivity coefficients to
examine the effects of dissipation on the KHI. Results - Enhancing the
viscosity and resistivity acts to suppress the KHI. Larger values delay the
formation of the instability and, in some cases, prevent the onset completely.
This leads to the earlier onset of heating for smaller values of the transport
coefficients. We note that viscosity has a greater effect on the development of
the KHI than resistivity. Furthermore, when using anomalous resistivity, the
Ohmic heating rate associated with the KHI may be greater than that associated
with the phase mixing that occurs in an instability-suppressed regime (using
uniform resistivity). Conclusions - From our study, it is clear that the
heating rate crucially depends on the formation of small length scales
(influenced by the numerical resolution) as well as the values of resistivity
and viscosity. As larger values of the transport coefficients suppress the KHI,
the onset of heating is delayed but the heating rate is larger. As increased
numerical resolution allows smaller length scales to develop, the heating rate
will be higher even for the same transport coefficients.
