Experimental Study on Venting of Lock Exchange Turbidity Current

Abstract

Dams are one of the most critical hydraulic structures worldwide. Sediment, entering the reservoirs of the dams with the water flow due to human interference in the dam catchment area, gradually destroys the functional storage through a deposition. Sedimentation threatens the sustainability of all reservoirs in the absence of adequate prevention and mitigation measures. Deposition of sediments in reservoirs can also affect the safe and proper operation of water intakes and bottom outlets belonging to the vital outlet structures. Turbidity currents are among the main impacts on dam reservoir sedimentation. One technique to decrease the impact of more sedimentation is to use bottom outlet gates that preserve the reservoir’s useable volume. This procedure may affect the quality of water exiting the dam. The present study experimentally investigated the venting of turbidity current of lock exchange with varying concentrations on the rigid bed, while there were two outlet gates with various levels and diameters at the same time. According to the available information, in the case of \({{Z0} \mathord{\left/ {\vphantom {{Z0} H}} \right. \kern-0em} H} = 0.3\), the average value of the concentrated input current was equal to the output concentration, which is the best level for the outlet gate installation based on the primary experimental conditios. The discharge efficiency is also higher when the inlet concentration is lower.