FLOW CHARACTERISTICS NEAR DRAINAGE GATES OF THE SAEMANGEUM TIDAL DIKE

摘要

The water level inside tidal dike depends on the operation of the drainage gates. The dischargethrough hydraulic structures is traditionally calculated by empirical formulas, which are derivedfrom dimensional analysis and laboratory experiments. However, in the situation where thefl ow does not have a directional preference or when there are multiple hydraulic structures, itis diffi cult to derive a valid empirical equation. In this study, the fl ow characteristics near thedrainage gates of the Saemangeum tidal dike are investigated by laboratory experiments, 3Dnumerical modeling and fi eld observations. Laboratory experiments were conducted usingthe 1:50 scale model of the tidal dike, drainage gate and the seabed topography. From theseexperiments, we derived the discharge diagrams that relate the discharge through the drainagegate and the water levels inside and outside of the dike for various operating conditions. Thenumerical simulations were also carried out using the commercial fl ow modeling software,FLOW-3D, and a previously developed in-house computational fl uid dynamics code. Ourresults show that the in-house CFD code outperforms the widely used commercial fl ow solverin reproducing the fl ow conditions selected from laboratory measurements. The dischargeand water elevations predicted by the numerical simulations are in good agreement with themeasurement, and it is shown that the CFD model is able to reproduce the complex fl owpatterns associated with the hydraulic jump occurring outside the tidal dike that was observedboth in the laboratory and fi eld.