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http://dx.doi.org/10.3741/JKWRA.2013.46.1.25

Dynamic Characteristics of Multiple Bars in the Channels with Erodible Banks  

Jang, Chang-Lae (Dept. of Civil Engineering, Korea National University of Transportation)
Publication Information
Journal of Korea Water Resources Association / v.46, no.1, 2013 , pp. 25-34 More about this Journal
Abstract
In this study, the development processes of multiple bars in the channels with erodible banks were investigated by double Fourier analysis. The initially straight channels in the experiment flume were widened with eroding the side banks, and the multiple bars were generated and grew due to stalling of the sediment on the bed. The bars migrated downstream and the size of the bars increased with time. The flow was separated around the bars, and the bed and banks near the bars were scoured due to the impinged secondary flow. The morphologic changes were accelerated by the bank erosion, which affected the fluctuations of sediment discharge downstream. The double Fourier analysis of the bed waves showed that 1-1 mode (alternate bar) was dominant at the initial stage of the channel development. As time increased, 2-3 mode (central or multiple bars) was dominant due to the increased width to depth ratio. Moreover, the number of bars in a cross section of the channel were increased due to the non linearity of alternate bars. The width to depth ratio was increased by the bank erosion, which affected the bar migration and the bar wavelength. However, the dimensionless tractive force was decreased by it.
Keywords
bank erosion; multiple bars; double fourier analysis; mode of bars;
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Times Cited By KSCI : 1  (Citation Analysis)
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