  In this work we explore the effect of binarity in the decretion disc of Be
stars, in order to explain their variability. To this aim, we performed
smoothed particle hydrodynamics (SPH) simulations on Be binary systems,
following the matter ejected isotropically from the equator of the Be star
towards the base of an isothermal decretion disc. We let the system evolve for
time long enough to be considered at steady state, and focus on the effect of
viscosity for coplanar prograde binary orbits. The disc structure is found to
be locked to the orbital phase, exhibiting also a dependence on the azimuthal
angle.
  Additionally, we present the first results from detailed non-local
thermodynamic equilibrium (non-LTE) radiative transfer calculations of the disc
structure computed with the SPH code. This is achieved by the use of the
three-dimensional (3D) Monte Carlo code HDUST, which can produce predictions
with respect to a series of observables.
