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An Analysis for the Characteristics of Headward Erosion and Separation Zone due to Bed Discordance at Confluence
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 Title & Authors
An Analysis for the Characteristics of Headward Erosion and Separation Zone due to Bed Discordance at Confluence
Choi, Heung Sik; Mo, Sun Jea; Lee, Sam Hee;
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 Abstract
The pattern of headward erosion at tributary and the separation zone formation in a loosed bed at confluence according to the confluence angle, discharge ratio, and dredging depth ratio have been analyzed. The separation zone is defined the inside of zero velocity boundary at downstream of confluence. The limit of separation zone occurrence is presented with dredging depth ratio. The propagation length of knickpoint increases as the confluence angle, discharge ratio, and dredging depth ratio increase in general and its regression equation has been suggested. The length and width ratios of separation zone in a loosed bed increase as discharge ratio and confluence angle increase as well as in a fixed bed. The length ratio decreases and the width ratio increases as dredging depth ratio increases results in great increase of shape factor and backwater rise by the conveyance reduction at confluence. The regression equation of shape factor with confluence angle, discharge ratio, and dredging depth ratio has been suggested.
 Keywords
separation zone;loosed bed;headward erosion;knickpoint migration;shape factor;
 Language
Korean
 Cited by
 References
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