  We present direct N-body simulations of black-hole-only clusters with up to
$2 \cdot 10^4$ compact objects, zero natal spin and no primordial binaries as
predicted by various primordial black hole (PBH) Dark Matter models. The
clusters' evolution is computed using ${\tt NBODY6\!+\!+GPU}$, including the
effects of the tidal field of the galaxy, the kicks of black hole mergers and
orbit-averaged energy loss by gravitational radiation of binaries. We
investigate clusters with four initial mass distributions, three of which
attempt to model a generic PBH scenario using a lognormal mass distribution and
a fourth one that can be directly linked to a monochromatic PBH scenario when
accretion is considered. More specifically, we dive into the clusters' internal
dynamics, describing their expansion and evaporation, along with the resultant
binary black hole mergers. We also compare several simulations with and without
black hole merger kicks and find modelling implications for the probability of
hierarchical mergers.
