Vortical dynamics of supercritical flows in the vicinity of hydraulic structures

Supercritical flows in the vicinity of hydraulic structures exhibit complex vortical dynamics governed by the interaction of three relevant hydrodynamic processes: (i) boundary layer separation at the front side of the obstacle; (ii) the presence of a horseshoe vortex system due to the negative pressure gradient, and (iii) unsteady oscillations of the free surface in the form of a hydraulic jump. In this investigation, we characterise the physical phenomena involved in this interaction for different Reynolds and Froude numbers. To describe the large-scale vortical structures, we present a novel numerical solver which combines an Artificial-Compressibility 3D Navier-Stokes solver with a Level-Set method with a geometric-based reinitialisation approach that ensures accurate mass-conservation. We focus on the momentum transport processes that connect the unsteady local dynamics of the three flow features described above and their effects on wake recovery, free-surface evolution, and bottom shear distribution.