IAHR, founded in 1935, is a worldwide independent member-based organisation of engineers and water specialists working in fields related to the hydro-environmental sciences and their practical application. Activities range from river and maritime hydraulics to water resources development and eco-hydraulics, through to ice engineering, hydroinformatics, and hydraulic machinery.
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You are here : eLibrary : IAHR World Congress Proceedings : 32nd Congress - Venice (2007) : THEME A: Engineering and Management of Fresh-water Systems : Effect of bedload movement on supercritical flow resistance in rigid boundary channels
Effect of bedload movement on supercritical flow resistance in rigid boundary channels
Author : M.H. OMID and A.R. HABIBZADEH
Movement of sediment particles along the bed in subcritical flow produces additional roughness to that without sediment transport. The magnitude of this bed load roughness is proportional to the thickness of the sediment layer moving along the bed, the particle size and the sediment concentration. In the case of supercritical flow, however, further resistance is expected due to momentum absorption of high flow velocity. In this study the effect of sediment movement on flow resistance in supercritical flow was experimentally investigated. The experiments consisted of creating supercritical flow conditions carrying sediment by injecting fine gravel (D50=5.42mm) into the flow in a rigid rectangular channel. Sediment was injected at the upstream at a rate just to produce bedload transport without any deposition. Sediment concentration was increased progressively by increasing the injection rate of sediment into the flow stream. The results show that the friction factor in supercritical flow is significantly increased as the sediment concentration along the bed is increased.
File Size : 371,458 bytes
File Type : Adobe Acrobat Document
Chapter : IAHR World Congress Proceedings
Category : 32nd Congress - Venice (2007)
Article : THEME A: Engineering and Management of Fresh-water Systems
Date Published : 01/07/2007
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