  Most, if not all, young stars are initially surrounded by protoplanetary
disks. Owing to the preferential formation of stars in stellar clusters, the
protoplanetary disks around these stars may potentially be affected by the
cluster environment. Various works have investigated the influence of stellar
fly-bys on disks, although many of them consider only the effects due to
parabolic, coplanar encounters often for equal-mass stars, which is only a very
special case. We perform numerical simulations to study the fate of
protoplanetary disks after the impact of parabolic star-disk encounter for the
less investigated case of inclined up to coplanar, retrograde encounters, which
is a much more common case. Here, we concentrate on the disk size after such
encounters because this limits the size of the potentially forming planetary
systems. In addition, with the possibilities that ALMA offers, now a direct
comparison to observations is possible. Covering a wide range of periastron
distances and mass ratios between the mass of the perturber and central star,
we find that despite the prograde, coplanar encounters having the strongest
effect on the disk size, inclined and even the least destructive retrograde
encounters mostly also have a considerable effect, especially for close
periastron passages. Interestingly, we find a nearly linear dependence of the
disk size on the orbital inclination for the prograde encounters, but not for
the retrograde case. We also determine the final orbital parameters of the
particles in the disk such as eccentricities, inclinations, and semi-major
axes. Using this information the presented study can be used to describe the
fate of disks and also that of planetary systems after inclined encounters.
