  With the use of high-resolution ALMA observations, complex structures that
resemble those observed in post-AGB stars and planetary nebulae are detected in
the circumstellar envelopes of low-mass evolved stars. These deviations from
spherical symmetry are believed to be caused primarily by the interaction with
a companion star or planet. With the use of three-dimensional hydrodynamic
simulations, we study the impact of a binary companion on the wind morphology
and dynamics of an AGB outflow. We classifiy the wind structures and morphology
that form in these simulations with the use of a classification parameter,
constructed with characteristic parameters of the binary configuration. Finally
we conclude that the companion alters the wind expansion velocity through the
slingshot mechanism, if it is massive enough.
