Experimental Investigation of Temporal Development of the Sediment Flushing Cone in Reservoirs Affected by DBE Structure

Reduction of reservoir storage capacity due to high rate of sedimentation affects all the purposes of dam operation, such as hydropower energy production and seasonal flood control. Using some sediment management techniques are not economically and technically affordable and one of the main solutions, especially in arid and semi-arid regions, is pressurized flushing that faced with low efficiency as a main challenge. In this research a new structure named DBE was used for enhancing sediment removal efficiency. Therefore DBE structure with four different lengths and four diameters in three discharges mode was investigated. For carrying out the experiments, non-cohesive silica sediment with a median diameter of  was used and temporal development of sediment flushing cone was investigated. Finally the best dimensions of the structure that leads to creation of the maximum sediment flushing cone dimensions and the minimum scouring equilibrium time were presented. Also, time dependent dimensionless equations for calculating the sediment flushing cone dimensions were presented.