  We present semi-analytical models and simplified $N$-body simulations with
$10^4$ and $10^5$ particles aimed at probing the role of dynamical friction
(DF) in determining the radial distribution of Blue Straggler Stars (BSSs) in
globular clusters. The semi-analytical models show that DF (which is the only
evolutionary mechanism at work) is responsible for the formation of a bimodal
distribution with a dip progressively moving toward the external regions of the
cluster. However, these models fail to reproduce the formation of the
long-lived central peak observed in all dynamically evolved clusters. The
results of $N$-body simulations confirm the formation of a sharp central peak,
which remains as a stable feature over the time regardless of the initial
concentration of the system. In spite of a noisy behavior, a bimodal
distribution forms in many cases, with the size of the dip increasing as a
function of time. In the most advanced stages the distribution becomes
monotonic. These results are in agreement with the observations. Also the shape
of the peak and the location of the minimum (which in most of the cases is
within 10 core radii) turn out to be consistent with observational results. For
a more detailed and close comparison with observations, including a proper
calibration of the timescales of the dynamical processes driving the evolution
of the BSS spatial distribution, more realistic simulations will be necessary.
