Investigation of the Impacts of Submerged Vanes on Pressurized Flushing in Reservoirs

Pressurized flushing is one of the techniques for evacuating sediments from reservoirs. In this study, the impact of submerged vanes on performance of pressurized flushing were investigated. For this purpose, submerged vanes with convergent, divergent and combined arrangements in three distances from the bottom outlet (), three middle distances () and three heights above the sediment bed () were used and the results were compared with the non structural test (reference test). The results showed that the submerged vanes by creating rotational flow and turbulence, enhanced the performance of flushing and also by evacuating much sediment below the bottom outlet, the amount of evacuated sediments increased in all experiments. As, in the convergent and divergent arrangements, the volume of evacuated sediments increased respectively 6.5 and 48 times compared to the non structural test. Also, in the combined arrangement with two-row divergent of submerged vanes, in 0.5, 0.3 and 1, the volume of flushing cone increased 51 times compared to reference test. Finally, by using a polynomial correlation with vane spacing, a non-dimensional equation for estimating the scour cone volume was proposed.