  Recent results from high-resolution solar granulation observations indicate
the existence of a population of small granular cells that are smaller than 600
km in diameter. These small convective cells strongly contribute to the total
area of granules and are located in the intergranular lanes, where they form
clusters and chains. We study high-resolution radiation hydrodynamics
simulations of the upper convection zone and photosphere to detect small
granular cells, define their spatial alignment, and analyze their physical
properties. We developed an automated image-segmentation algorithm specifically
adapted to high-resolution simulations to identify granules. The resulting
segmentation masks were applied to physical quantities, such as intensity and
vertical velocity profiles, provided by the simulation. A new clustering
algorithm was developed to study the alignment of small granular cells. This
study shows that small granules make a distinct contribution to the total area
of granules and form clusters of chain-like alignments. The simulation profiles
demonstrate a different nature for small granular cells because they exhibit on
average lower intensities, lower horizontal velocities, and are located deeper
inside of convective layers than regular granules. Their intensity distribution
deviates from a normal distribution as known for larger granules, and follows a
Weibull distribution.
