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Modelling Dynamic Bed Roughness Associated with Bed Form Development
2009In this study bed form development was quantified and used to calculate a dynamic bed roughness parameter. An algorithm that can be readily implemented into numerical models was developed and evaluated for two scenarios, with distinct flow conditions and sediment carrying capacities.
Rauen W B, Lin B
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Bed-Material Transport and Bed Forms
Journal of the Hydraulics Division, 1972Because the control of sediment transport is the rate that particles can be removed from the surface of the bed, the geometry of the bed must be a dominant factor in bed-material transport. Bed geometry can be classified by the amplitude of sand waves into three regions increasing amplitude, decreasing amplitude, and flat bed.
Marion R. Carstens, Hilmi D. Altinbilek
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Journal of Hydraulic Engineering, 1994
Based upon the results of a series of 47 bed‐development experiments, the evolution of bed features subsequent to their initial generation from flat bed conditions is examined. For each such experiment, bed profiles were measured at frequent time intervals as sand‐wave configurations developed under the action of open‐channel water flow.
Stephen E. Coleman, Bruce W. Melville
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Based upon the results of a series of 47 bed‐development experiments, the evolution of bed features subsequent to their initial generation from flat bed conditions is examined. For each such experiment, bed profiles were measured at frequent time intervals as sand‐wave configurations developed under the action of open‐channel water flow.
Stephen E. Coleman, Bruce W. Melville
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Initiation of Bed Forms on a Flat Sand Bed
Journal of Hydraulic Engineering, 1996The results of a series of 47 bed development experiments are combined with appropriate experimental results of other authors. The generation of initial bed waves, termed sand-wavelets, on a plane sand bed is found to be instigated by the occurrence of a random pileup of sediment, this pileup subsequently growing as further sediment is trapped by the ...
Stephen E. Coleman, Bruce W. Melville
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ON BED FORMS AND PALAEOCURRENTS
Sedimentology, 1966SUMMARYBed forms arise by interaction between a fluid flow and the sediment transported over or close to the bed. The geometry of bed forms is two‐dimensional or three‐dimensional. Two‐dimensional bed forms generate two‐dimensional internal sedimentary structures and are adjusted to two‐dimensional flow‐vector fields.
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2009
Aeolian bedforms range in size from small-scale (ripples), through medium-scale (dunes) to large-scale (megadunes or draa). This chapter describes the physical characteristics and development of each of these bedform types, including their relationship to airflow and sand transport at different spatial and temporal scales.
Kenneth Pye, Haim Tsoar
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Aeolian bedforms range in size from small-scale (ripples), through medium-scale (dunes) to large-scale (megadunes or draa). This chapter describes the physical characteristics and development of each of these bedform types, including their relationship to airflow and sand transport at different spatial and temporal scales.
Kenneth Pye, Haim Tsoar
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1999
The movement of sediments as bed load and suspended load usually refers to their movement as individual particles. Yet while sediment is being transported, the bed load particles move collectively in all sorts of ways along the river bed. Their motion in tum can cause changes in the configuration of the river bed in accordance with the variation of ...
Ning Chien, Zhaohui Wan
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The movement of sediments as bed load and suspended load usually refers to their movement as individual particles. Yet while sediment is being transported, the bed load particles move collectively in all sorts of ways along the river bed. Their motion in tum can cause changes in the configuration of the river bed in accordance with the variation of ...
Ning Chien, Zhaohui Wan
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Journal of Geophysical Research: Oceans, 2003
Fluid flow interacts with sedimentary beds forming waves of different kinds, which are of considerable practical importance since they influence significantly the near‐bed flow, both over and below the bed, sediment transport, and wave height attenuation. We focus here on steep bed forms capable of producing flow separation.
Luis A. Giménez‐Curto +1 more
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Fluid flow interacts with sedimentary beds forming waves of different kinds, which are of considerable practical importance since they influence significantly the near‐bed flow, both over and below the bed, sediment transport, and wave height attenuation. We focus here on steep bed forms capable of producing flow separation.
Luis A. Giménez‐Curto +1 more
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Bed-Form Geometry in Sand-Bed Flows
Journal of Hydraulic Engineering, 1999A new method is proposed for predicting relative bed-form height h/d in sand-bed flows. The proposed method is based on the concept of relating energy loss due to form drag to the head loss across a sudden expansion in open channel flows. A unique feature of the proposed method is that it can be applied to various bed forms, i.e., ripples, dunes ...
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Role of Near‐Bed Turbulence Structure in Bed Load Transport and Bed Form Mechanics
Water Resources Research, 1995The interactions between turbulence events and sediment motions during bed load transport were studied by means of laser‐Doppler velocimetry and high‐speed cinematography. Sweeps (u′ > 0, w′ < 0) which contribute positively to the mean bed shear stress, collectively move the majority of the sediment, primarily because they are extremely common ...
Jonathan M. Nelson +3 more
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