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2 edition of Meander changes in relation to bend morphology and secondary flows. found in the catalog.

Meander changes in relation to bend morphology and secondary flows.

J. Hooke

Meander changes in relation to bend morphology and secondary flows.

by J. Hooke

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  • 12 Currently reading

Published .
Written in English


ID Numbers
Open LibraryOL19119983M

Persistent secondary flow (vortical) structures as observed experimentally in planar cross sections have been associated with flow instabilities. This study presents the results of two rigorous in vitro experimental investigations of secondary flow structures within a .   Meander behaviour in relation to slope characteristics. Paper presented at conference on River Meandering, New Orleans, American Society of Civil Engineers. Google Scholar.

AbstractThe purpose of this study is to characterize the swirling secondary flow in the downstream of a pipe bend using a numerical simulation of the flow. The CFD (Computational Fluid Dynamics) software OpenFOAM is used to simulate the turbulent flow in pipes with elbow. Various turbulence models are benchmarked with the existing experimental data and a comparative study is performed to. Flow structure at various flow stages is related to changes in bed morphology over the study timeframe. Increases in local curvature within the upstream lobe of the bend reduce outer bank velocities at morphologically significant flows, creating a region that protects the bank from high momentum flow and high bed shear stresses.

[6] In reduced‐order meander models, the secondary flow (Figure 1) is a main driving force of the velocity excess. This secondary flow is related to the river planform and can primarily be expressed as a convolution function of the channel curvature [Güneralp and Rhoads, ]. This sec-ondaryflowinduces atransverse componentof thebedshear. secondary flow intensity for small curvature radius bend and a straight pipe after a 90 ̊ elbow respectively. Boiron et al. () looked at the maximum secondary flow velocity when analyzing an oscillatory flow in a U-bend. Vorticity magnitudes and location of core vortex were observed by Sudo et al. (), Vester et al.


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Meander changes in relation to bend morphology and secondary flows by J. Hooke Download PDF EPUB FB2

Meander Changes in Relation to Bend Morphology and Secondary Flows. Hooke. Department of Geography, Portsmouth Polytechnic, UK The changes in meander patterns since have been identified from maps, air photographs and field survey for a 14 km reach of the River Dane in Cheshire, England, with a mobile meandering channel Cited by: Flow structure at various flow stages is related to changes in bed morphology over the study timeframe.

the stability of the flow perimeter and the bend morphology. of secondary flow. This study has documented the response of 3-D flow structure and channel morphology at a confluent meander bend to changes in momentum-flux ratio. The results show that the entry of tributary flow near the apex of a bend greatly alters patterns of flow and bed morphology from patterns typically found in meander by: A meander is one of a series of regular sinuous curves, bends, loops, turns, or windings in the channel of a river, stream, or other watercourse.

It is produced by a stream or river swinging from side to side as it flows across its floodplain or shifts its channel within a valley. A meander is produced by a stream or river as it erodes the sediments comprising an outer, concave bank and.

Request PDF | Flow structure and channel morphology at a natural confluent meander bend | Previous experimental, field, and modeling studies of confluence dynamics have focused mainly on junctions.

An oxbow lake is a U-Shaped lake that forms when a wide meander of a river is cut off, creating a free-standing body of south Texas, oxbows left by the Rio Grande are called Australia, oxbow lakes are called lakes are also found in India.

The word "oxbow" can also refer to a U-shaped bend in a river or stream, whether or not it is cut off from the main stream. Secondary flows within the river appear connected to: i) large-scale channel curvature, linked to the large bends, ii) topographic forcing of flow by the local bed morphology, such as divergence and convergence of flow over and around the mid-channel bars, and iii) flow wakes on the lee side of ship wrecks.

The trend for the intensity of secondary flow shows an increase in the first part of the bend until a maximum value at 60° to the bend, and then decreases in the second part of the bend. CiteSeerX - Document Details (Isaac Councill, Lee Giles, Pradeep Teregowda): The spatial distribution of large woody debris (LWD) within a river channel has a complex, but influential, relationship with channel morphology.

This study examines the spatial distribution of LWD, present as both jams and singular logs, and its relationship with the channel morphology of the Bitterroot River in.

[1] This paper documents the three‐dimensional structure of flow and bed morphology of two developing chute cutoffs on a single meander bend on the lower Wabash River, USA, and relates the flow structure to patterns of morphologic change in the evolving cutoff channels.

The upstream end of the cutoff channels is characterized by: (1) a zone of flow velocity reduction/stagnation and bar. Hooke, JM, Harvey, AM () Meander changes in relation to bend morphology and secondary flows (River Dane, Cheshire). In: Collinson, JD, Lewin, J (eds) Modern and Ancient Fluvial Systems.

International Association of Sedimentologists Special Publication 6. Oxford: Blackwell, – Google Scholar. KEYWORDS:velocity transverse distribution, secondary flow, river, meander. 1- INTRODUCTION Studying flow hydraulics in bends has always been in the focus of researchers.

In bend, variations of flow depth, velocity, and shear stress in width of rivers are always high causing secondary flow and friction of outer bend as well as sedimentation in. A further phenomenon, the outer secondary cell, which was discovered and described for the first time by Thorne and Hey and Thorne et al.

[29,30] some decades ago, recently came into focus aert recreated the conditions for the outer secondary cell in a flume [6,31].Blanckaert and Graf explained a change in the downstream momentum due to a change in curvature [].

3 of 15 98 Overall, three questions arise based on the above review: (1) whether secondary flow effects 99 can be reflected by secondary flow models on flow field in such mega meandering rivers; (2) which model should be given priority to flow simulation in meandering channels of such scale; (3) what the temporal influence of secondary flow is on bed morphology variations associated.

The effect on meander wavelength selection depends on the location of the widest section relative to the bend apex. Under typical formative conditions of gravel-bed rivers, with large-enough channel aspect ratios, two distinct most unstable longitudinal modes develop.

Flow structure and channel morphodynamics of meander bend chute cutoffs: A case study of the Wabash River, USA Jessica A. Zinger,1 Bruce L. Rhoads,1,2,3 James L. Best,1,2,3,4 and Kevin K. Johnson5 Received 25 October ; revised 23 September ; accepted 25 September ; published 12 December   The planform evolution of meandering river bends is dominated by secondary (across-channel) helical flow, which causes point-bar deposition on the inner-bend, and erosion of the outer-bend.

Based on the validation for low-flow condition, 3D simulations were carried out for medium and high flows where the bendway weirs are completely submerged. These simulations indicate that 3D patterns of flow, especially flow near the outer bank, change dramatically with changes in flow stage.

The flow pattern in the confluent meander bend channel under the conditions of different discharge ratios and junction angles is numerically simulated by means of the large eddy simulation (Les), and the characteristics of the flow separation zone are analyzed. Numerical results are well validated by experimental data with a good agreement.

Few researches focus on secondary flow effects on bed deformation caused by cohesive sediment deposition in meandering channels of field mega scale.

A 2D depth-averaged model is improved by incorporating three submodels to consider different effects of secondary flow and a module for cohesive sediment transport.

These models are applied to a meandering reach of Yangtze River to investigate. Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business.The aim of this study is to offer new insights regarding flow-induced morphological changes in meander using a novel study approach.

We focused on short-term and small-spatial-scale changes by conducting a spatially and temporally (daily) intensive survey during a flood (a period of nine days) with an ADCP attached to a remotely controlled mini.Usually, channels in a flood plain are meandering.

A meander is a sinuous bend in a river, and a river may meander continuously for hundreds of kilometers through a flood plain. The term is derived from the River Meanderes in Turkey. If a meandering channel has been rejuvenated, a channel begins to under-cut a river bed while keeping.