Discharge Characteristics of Drainage Gates on Saemangeum Tidal Dyke, South Korea

Abstract

In this study, the discharge characteristics through the drainage gates of the Saemangeum tidal dyke were investigated by laboratory experiments, 3D numerical modelling, and field observations. Laboratory experiments were conducted using a 1:50 scale model of the tidal dyke, drainage gate, and seabed topography and field observations were used to validate the experimental results. From the results of these experiments, we derived discharge diagrams that relate the discharge through the drainage gate to the water levels inside and outside the dyke for a range of operating conditions. The formula and discharge coefficients were suggested for free and submerged flows through hydraulic experiments. The discharge predicted from suggested formula agreed well with experimental results. Discharge coefficients of half gates open cases are slightly less than those of all gates open cases due to flow disturbance along the side of downstream. Through experiments with two drainage gates, the Sinsi and Garyok gates, it was found that the discharge coefficients were highly influenced by the terrain around the gates. Numerical simulations were also carried out using a commercial flow modelling software (FLOW-3D). The discharge and flow patterns predicted by the numerical simulations were found to be in good agreement with the measurements.