  The BARC flow is studied via Direct Numerical Simulation at a relatively low
turbulent Reynolds number, with focus on the geometrical representation of the
leading-edge (LE) corners. The study contributes to further our understanding
of the discrepancies between existing numerical and experimental BARC data. In
a first part, rounded LE corners with small curvature radii are considered.
Results show that a small amount of rounding does not lead to abrupt changes of
the mean fields, but that the effects increase with the curvature radius. The
shear layer separates from the rounded LE at a lower angle, which reduces the
size of the main recirculating region over the cylinder side. In contrast, the
longitudinal size of the recirculating region behind the trailing edge (TE)
increases, as the TE shear layer is accelerated. The effect of the curvature
radii on the turbulent kinetic energy and on its production, dissipation and
transport are addressed. The present results should be contrasted with the
recent work of Rocchio et al, JWEIA 2020, who found via implicit Large-Eddy
Simulations at larger Reynolds numbers than even a small curvature radius leads
to significant changes of the mean flow.
  In a second part, the LE corners are fully sharp and the exact analytical
solution of the Stokes problem in the neighborhood of the corner is used to
locally restore the solution accuracy degraded by the singularity. Changes in
the mean flow reveal that the analytical correction leads to streamlines that
better follow the corners. The flow separates from the LE with a lower angle,
resulting in a slightly smaller recirculating region. The corner-correction
approach is valuable in general, and is expected to help developing
high-quality numerical simulations at the high Reynolds numbers typical of the
experiments with reasonable meshing requirements.
