  Alfv\'en-wave turbulence has emerged as an important heating mechanism to
accelerate the solar wind. The generation of this turbulent heating is
dependent on the presence and subsequent interaction of counter-propagating
alfv\'en waves. This requires us to understand the propagation and evolution of
alfv\'en waves in the solar wind in order to develop an understanding of the
relationship between turbulent heating and solar-wind parameters. We aim to
study the response of the solar wind upon injecting monochromatic
single-frequency alfv\'en waves at the base of the corona for various magnetic
flux-tube geometries. We used an ideal magnetohydrodynamic (MHD) model using an
adiabatic equation of state. An Alfv\'en pump wave was injected into the quiet
solar wind by perturbing the transverse magnetic field and velocity components.
Alfv\'en waves were found to be reflected due to the development of the
parametric decay instability (PDI). Further investigation revealed that the PDI
was suppressed both by efficient reflections at low frequencies as well as
magnetic flux-tube geometries.
