مشخصات پژوهش

Dam construction reduces flow velocity, causing sediment accumulation in reservoirs and shortening dam lifespan. Among various sediment management approaches, free-flow flushing is considered an effective strategy for improving sediment removal efficiency. Despite its potential, the influence of outlet shape on flushing efficiency (FE) remains insufficiently studied. This study investigates the effects of outlet shape, inflow discharge (Qin), and sediment level (hs) on FE through 48 large-scale flume experiments, involving four outlet shapes, three sediment levels, and four discharges. Results indicate that increasing the Froude number (Fr = 1.22–2.13) enhances FE by 5–11% in the optimal model. Higher sediment levels were directly associated with greater flushing volumes, with the most efficient model showing a 14% increase in FE at