  The fundamental difference between accretion around black holes and neutron
stars is the inner boundary condition, which affects the behavior of matter
very close to the compact objects. This leads to formation of additional shocks
and boundary layers for neutron stars. Previous studies on the formation of
such boundary layers focused on Keplerian flows that reached the surface of the
star, either directly or through the formation of a transition layer. However,
behavior of sub-Keplerian matter near the surface of a neutron star has not
been studied in detail. Here, we study the effect of viscosity, in presence of
cooling, on the sub-Keplerian flows around neutron stars, using Smoothed
Particle Hydrodynamics. Our time-dependent study shows that multiple shocks,
transition and boundary layers form in such type of accretion, when viscosity
is significant, and one or more layers are absent when the viscosity is
moderate. These flows are particularly of interest for the wind dominated
systems such as Cir X-1. We also report the formation of a generalized flow
configuration, Two-Component Advective Flow, for the first time.
