This work consists in a numerical and experimental investigation on the BARC benchmark, dealing with the flow around a 5:1 rectangular cylinder. The effects of varying spanwise grid resolution, SGS dissipation and, finally, upstream edge rounding have been evaluated. In particular, I highlight the effect produced on flow features, on characteristic frequencies and spanwise correlations, in order to emphasize the causes of the discrepancy of various results. Numerical simulations have been performed by means of LES simulations, experimental investigation have been carried out by means of pressure and velocity measurements in the wind tunnel.