DNS of separated flow: Scale-by-scale analysis

The Direct Numerical Simulation (DNS) of a turbulent channel containing a bump is carried out to study the turbulence dynamics in the separated region. Our study is intended to fill the gap among the idealised conditions, e.g. plane channel flows typically addressed in literature and the actual flow geometries where the effects of wall curvature and the presence of bluff bodies immediately generate a substantial separated flow region in the bulk of the flow and produce turbulent wakes behind the bluff body. Such configuration allows retaining, with the minimum level of complexity, all the basic features of separated wall-bounded flows such as the presence of the recirculating region that acts as the main energy source for the turbulent velocity fluctuations in the bulk of the flow and in the wake behind the bump.