Analysis of flow characteristics around islands due to semi-diurnal currents in the Han River, Korea

• Published in: KSCE journal of civil engineering 2015, 19(6), , pp.1905-1915
• Main Authors: Seo, Il Won, Kim, Young Do, Song, Chang Geun
• Format: Article
• Language: English
• Subjects: Artificial islands; Civil Engineering; Construction; Diurnal; Diurnal variations; Engineering; Flood flow; Floods; Flow characteristics; Geotechnical Engineering & Applied Earth Sciences; Industrial Pollution Prevention; Islands; Reduction; Rivers; Two dimensional flow; Unsteady; Unsteady flow; Velocity; Velocity distribution; Water depth; Water Engineering; 토목공학
• ISSN: 1226-7988; 1976-3808
• DOI: 10.1007/s12205-014-0237-4

In this study, an unsteady 2D depth-averaged flow model by Petrov-Galerkin stabilization was developed to investigate flow characteristics caused by semi-diurnal current at the tidal reach of the Han River. In order to analyze the velocity field around islands located in the mid-course of the Han River, simulations of the transient flow were conducted with principal lunar and solar semidiurnal constituent conditions. In addition, the influence of an artificial island construction located at the tributary confluence was quantitatively examined. The results show that, under normal flow condition, around Bam Island, main flow was inclined to the left half of the river span, and the velocity reversal was occurred during the flood tide which would result in the deposition sediment to form the Island. Under bank-full flood condition, velocities around No-deul Island were higher than those around Seon-yu Island reaching 3.5 m/s in maximum. The construction of the artificial island at the Jung-nang Stream confluence caused the significant reduction in the flood conveyance of the Han River and 90% increase in maximum velocity during the bank-full flood flow condition.