Variability of flow velocity induced by Dongsam Seawater Stream Floodgate installation

Abstract

The Dongsam seawater stream on a reclaimed land flows by tidal forcing. The flow in generally slow, especially in the central portion of the stream because the outflow and inflow each occurs at both ends of the stream simultaneously. As a result, sediments accmulate constantly with the deteorating water quality. In this study, field observation was conducted using Aquadrifter and Aquadopp and analyzed for the analysis of the flow velocity in the stream. The computational fluid dynamics (CFD) modeling was run with and without Seawater Stream Floodgate to predict the variability of the flow. The flow velocity of the Dongsam Seawater Stream was recorded in the range of 0.01 ~ 0.13 m/s, and the tidal range was within 1.0 m. According to the simulation, the flow velocity could increase remarkably with two floodgates used to force the stream to flow unidirectionally (toward Korea Maritime & Ocean University). The flow velocity change rate at each point is recorded -97 ~ 638% at P1 (front of Malfunction Floodgate near Busan Int. Cruise Terminal), -89 ~ 659% at P2 (back of Malfunction Floodgate near Busan Int. Cruise Terminal), -100 ~ 1198% at P3 (central channel), and at P4 (toward Korea Maritime & Ocean University) was -100 to 1163%, and Case III-a showed the largest flow velocity rate increase in the central part. Therefore, if two Floodgates are installed and flowed out toward Korea Maritime & Ocean University, the flow velocity rate of the Stream can be increased.