  Slug flows are a typical intermittent two-phase flow pattern that can occur
in submarine pipelines connecting the wells to the production facility and that
is known to cause undesired consequences. In this context, computational fluid
dynamics appears to be the tool of choice to understand their formation.
However, few direct numerical simulations of slug flows are available in the
literature, especially using meshless methods which are known to be capable of
handling complex problems involving interfaces.
  In this work, a 2D study of the instability processes leading to the
formation of intermittent flows in pipes is conducted using an existing
multiphase smoothed particle hydrodynamics formulation associated with inlet
and outlet boundary conditions. This paper aims to demonstrate the
applicability of smoothed particle hydrodynamics to a given set of
close-to-industry cases.
  First, we check the ability of our implementation to reproduce flow regimes
predicted by Taitel and Duckler's flow map. Then, we focus on the transition
processes from one flow pattern to the other. Finally, we present the results
obtained for more realistic cases with high density and viscosity ratios.
