5 documents found, page 1 of 1
Time evolution of the scour induced by a ski jump jet
Santos, R.; Carvalho, E.; Lima, M. M. C. L.; Aleixo, R.Scour studies are often made at the equilibrium stage when the scour hole is stabilized and no more changes in the scour geometry occur. However, studying the scour time evolution is critical to better understand the erosion process and the main factors that control it in the short and long terms. Scour is a destructive process, therefore, in the absence of non-intrusive and real-time measurement techniques, an...
Effect of the ski jump bucket angle on the scour hole downstream of a convergin...
Sá Machado, L.; Lima, M. M. C. L.; Aleixo, R.; Carvalho, E.The present study is devoted to the analysis of scour downstream of a converging stepped spillway equipped with a ski jump bucket. The energy dissipated by jets leaving the spillway can be divided in two parts: one is the kinetic energy dissipated along the jet trajectory and another one is the energy dissipated on the impact with the tailwater. Due to the jet impact, the riverbed is subjected to turbulent pres...
Determinação dos campos de velocidades de escoamentos bifásicos usando PIV-PTV
Aleixo, R.; E. Carvalho; Lima, M. M.; Ferreira, R.
LDV measurements of the flow induced by an elongated bridge pier: the fixed bed...
Lima, Maria Manuela Carvalho Lemos; Carvalho, E.; Aleixo, R.Elongated piers are a commonly found geometry in bridge pier design. This paper addresses the study of the flow around an elongated bridge pier, since not many studies exists concerning this geometry. To better understand the features of such pier geometry a set of measurements made upstream and down-stream of an elongated bridge pier are presented. Mean and turbulent variables are presented and emphasis is giv...
Experimental study of the bed morphology downstream of a sluice gate
Carvalho, L.; Carvalho, E.; Aleixo, R.; Lima, M. M. C. L.This work describes an experimental study based on a simplified model of a vertical sluice gate installed in a channel with a moving bed of glass spheres with 2 mm diameter. The originated scour cavity and downstream dune were studied. The influence of the apron length and the downstream tailwater depth were also analysed. Imaging techniques provided the tools to this investigation. The data acquisition and pro...