Investigation the phenomenon of sediment flushing under submerged condition in the upstream of dams using physical model

In the sediment washing method under submersible flow, the volume of the discharged sediments depends on various parameters, which can be referred to the depth of the water inside the tank, the depth of the water inside the pond, the output flow from the lower discharger, the size and type of accumulated sediments inside the tank. did To check the mentioned parameters in this research, a physical model with a length of 1 meter, a width of 1 meter and a height of 1.10 meters and by performing various tests using 2 water heights inside the tank, 3 water heights inside the pond and with 3 types of sediment granulation (in total 18 experiments) were investigated and studied. The results of this research show that in sediment washing under pressure, when the lower discharger returns for sediment washing, a sediment washing cone is formed in front of it. The dimensions of the formed sediment washing cone depend on the discharge from the lower discharger, the height of the water inside the tank and the diameter of the sediments accumulated inside the tank, so that the measurement results show that in order to keep the height of submerged water constant, the height of water inside the tank increases. It increases the volume and length of the sediment washing cone. Also, for a fixed water height inside the tank, increasing the submerged water height increases the volume and length of the sediment washing cone.