Experimental study of fish-friendly angled bar racks with horizontal bars

This paper presents an experimental study of angled fish-friendly bar racks with horizontal bars, using a physical model in open channel. Head losses are investigated for two shapes, three ratios between spacing and thickness four angles orientation the racks. The Froude bar-Reynolds numbers were respectively 0.275 3600. head loss coefficients decrease as blockage ratio angle rack decrease. They well predicted by formula produced previously inclined rack, some adaptations. Velocity fields characterized upstream downstream racks, showing no effect heterogeneity over channel width. Consequently, normal tangential components velocity along agreement theoretical values given angular decomposition. These results serve to assess compliance biological criteria avoid impingement risks guide fish towards bypass.