Secondary Currents with Scour Hole at Grade Control Structures

Most studies on local scouring at grade control structures have principally focused the analysis of primary flow field, predicting equilibrium scour depth. Despite numerous processes, secondary currents were not often considered. Based comprehensive measurements velocities in clear water scours downstream a structure channel with non-cohesive sediments, this study, we attempted to investigate generation and turbulence properties across hole condition. The velocity distributions through cross-sectional planes location maximum depth clearly show development current cells. form sort helical-like motion, occurring both halves cross-section an axisymmetric fashion. A detailed intensities Reynolds shear stresses was carried out compared previous studies. results highlight considerable spatial heterogeneities turbulence. anisotropy term normal dominates stress, giving impression its crucial role generating motion hole. shows values near mouth bed, caused, respectively, by sediment ridge formation, which play fundamental roles maintaining enhancing motion.