  We have investigated the effect of sheared equilibrium flows on the $m = 1, n
= 1$ resistive internal kink mode in the framework of a reduced
magnetohydrodynamic model in a periodic cylindrical geometry. Our numerical
studies show that there is a significant change of the scaling dependence of
the mode growth rate on the Lundquist number in the presence of axial flows
compared to the no flow case. Poloidal flows do not influence the scaling. We
have further found that viscosity strongly modifies the effect of flows on the
(1,1) mode both in the linear and nonlinear regime. Axial flows increase the
linear growth rate for low viscosity values, but they decrease the linear
growth rate for higher viscosity values. In the case of poloidal flows the
linear growth rate decreases in all cases. Additionally at higher viscosity, we
have found strong symmetry breaking in the behaviour of linear growth rates and
in the nonlinear saturation levels of the modes as a function of the helicities
of the flows. For axial, poloidal and most helical flow cases, there is flow
induced stabilisation of the nonlinear saturation level in the high viscosity
regime and destabilisation in the low viscosity regime.
