Transport and deposition of fine sediment in open channels with different aspect ratios |
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Authors: | Jing Bai Hongwei Fang Thorsten Stoesser |
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Institution: | 1. State Key Laboratory of Hydro Science and Engineering, Department of Hydraulic Engineering, Tsinghua University, , Beijing, 100084 China;2. School of Civil and Environmental Engineering, Georgia Institute of Technology, , Atlanta, GA, 30332 USA |
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Abstract: | This paper investigates by means of several large eddy simulations how the channel aspect ratio affects the transport and settling of suspended sediments. The numerical method is successfully validated using data of a physical experiment of fine sediment net deposition in an open channel flow. The channel aspect ratio, A, is known to be the determining factor for the development, strength and distribution of the turbulence‐driven secondary flow, and it is demonstrated that A influences the primary flow, turbulence quantities and the transport and fate of fine sediments. The secondary flow locally supports or hinders the falling of fine sediment particles in a turbulent flow, which results in a non‐uniform deposition of fine sediments over the cross‐section. While the channel aspect ratio has a large influence on the distribution of suspended sediments within the cross‐section, its effect on the cross‐sectional averaged deposition is negligibly small. Copyright © 2012 John Wiley & Sons, Ltd. |
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Keywords: | fine sediments net deposition sediment transport secondary flow open channel flow LES |
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