Energy dissipation in submerged block ramps at fixed slopes

The aim of the paper is to investigate the relative energy dissipation that occurs in submerged block ramps conditions. Block ramps generally produce high energy dissipation. Most of the previous studies were confined in finding the energy dissipation throughout the ramp. The energy dissipation and flow conditions when the ramp is submerged have received relatively little attention, whereas this type of condition can often take place in case of high discharge and fluvial flow conditions. The present study shows the result of the experimental investigations conducted at Hydraulic Laboratory of the University of Pisa, Pisa, Italy on ramps characterized by different bed materials and different submerged conditions keeping constant the ramp slope. The experiments were carried out for a slope of 1V:6H in different submerged ramp conditions. The study shows that the energy loss varying jump location on the ramp is function of scale roughness, the ratio between the critical water depth and ramp height and the ratio between the ramp length and the reduced ramp length in submerged condition. The present study also investigates the differences in energy dissipation for submerged jump in different bed conditions such as fixed smooth bed and mobile bed.