Hydrodynamical simulations of Galactic fountains II: evolution of
  multiple fountains
  Using 3D hydrodynamical simulations, we studied in detail the fountain flow
and its dependence with several factors, such as the Galactic rotation, the
distance to the Galactic center, and the presence of a hot gaseous halo. We
have considered the observed size-frequency distribution of young stellar
clusters within the Galaxy in order to appropriately fuel the multiple
fountains in our simulations. The present work confirms the localized nature of
the fountain flows: the freshly ejected metals tend to fall back close to the
same Galactocentric region where they are delivered. Therefore, the fountains
do not change significantly the radial profile of the disk chemical abundance.
The multiple fountains simulations also allowed to consistently calculate the
feedback of the star formation on the halo gas. Finally, we have also
considered the possibility of mass infall from the intergalactic medium and its
interaction with the clouds that are formed by the fountains. Though our
simulations are not suitable to reproduce the slow rotational pattern that is
typically observed in the halos around the disk galaxies, they indicate that
the presence of an external gas infall may help to slow down the rotation of
the gas in the clouds and thus the amount of angular momentum that they
transfer to the coronal gas, as previously suggested in the literature.
