• Title/Summary/Keyword: Local scour hole

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Numerical investigation of space effects of serial spur dikes on flow and bed changes by using Nays2D (수치모형을 이용한 수제 간격에 따른 흐름 및 하도변화 연구)

  • Lee, Kyung Su;Jang, Chang-Lae
    • Journal of Korea Water Resources Association
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    • v.49 no.3
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    • pp.241-252
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    • 2016
  • In this study, the characteristics of flow and bed changes with variation of space and length of serial spur dikes were investigated with 2 dimensional numerical simulation. Upstream spur dike was affected by flow and made a role as a single spur dike. As time increased, local scouring was developed around outside of spur dike, and migrated upstream. The aggradation of the bed at the back of spur-dike was made at the initial stage of experiment and numerical modelling. However, the aggradation of the bed was increased in the downstream area. The scour whole around a spur dike upstream was not deep as the Dimensionless spur-dike interval (b) of the dike increased. The depth of scour hole was nearly constant at the dynamic equilibrium state. The dimensionless scour depth ($y_s/H$) increased with L/b. The spur dike downstream had the characteristics of single spur dike as the L/b was larger than 10. However, the spur dike downstream was affected by the dike upstream as the L/b was less than 4, and the bed of the upstream in the spur dike was aggradated and the effects of the serial spur dikes on the bed decreased.