A method for the formulation of Reynolds number functions

2000 ◽  
Vol 27 (4) ◽  
pp. 829-833 ◽  
Author(s):  
Ana Maria AF da Silva ◽  
Tirupati Bolisetti
Keyword(s):  
Reynolds Number ◽  
Sediment Transport ◽  
Flow Characteristics ◽  
Mathematical Expression ◽  
Open Channels ◽  
Strong Variation ◽  
Mathematical Expressions ◽  
Flow And Sediment Transport ◽  
Shields Curve ◽  
General Method

A general method for the formulation of flow characteristics which are functions of the Reynolds number of the system is presented. It is assumed that the flow characteristics exhibit a strong variation with the Reynolds number when the Reynolds number is "small," and that they become independent of it when the Reynolds number is "large." The method is illustrated by finding mathematical expressions for the experimentally determined "roughness" function curve and for the sediment transport initiation curve (Shields' curve), which are relevant for the analysis of flow and sediment transport in pipes and open channels. The two expressions thus obtained can be used in practice for computational purposes.Key words: Reynolds number functions, mathematical expression, roughness function, Shields' curve.

scholarly journals A Shear Reynolds Number-Based Classification Method of the Nonuniform Bed Load Transport

Water ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 73 ◽  
Author(s):  
Gergely T. Török ◽  
János Józsa ◽  
Sándor Baranya
Keyword(s):  
Reynolds Number ◽  
Sediment Transport ◽  
Comparative Assessment ◽  
Bed Load ◽  
Laboratory Measurements ◽  
Strong Variation ◽  
Load Transport ◽  
Bed Load Transport ◽  
Novel Method ◽  
Bed Material

The aim of this study is to introduce a novel method which can separate sand- or gravel-dominated bed load transport in rivers with mixed-size bed material. When dealing with large rivers with complex hydrodynamics and morphodynamics, the bed load transport modes can indicate strong variation even locally, which requires a suitable approach to estimate the locally unique behavior of the sediment transport. However, the literature offers only few studies regarding this issue, and they are concerned with uniform bed load. In order to partly fill this gap, we suggest here a decision criteria which utilizes the shear Reynolds number. The method was verified with data from field and laboratory measurements, both performed at nonuniform bed material compositions. The comparative assessment of the results show that the shear Reynolds number-based method operates more reliably than the Shields–Parker diagram and it is expected to predict the sand or gravel transport domination with a <5% uncertainty. The results contribute to the improvement of numerical sediment transport modeling as well as to the field implementation of bed load transport measurements.

Developing a 2D vertical flow and sediment transport model for open channels using the Youngs-VOF method

2016 ◽  
Vol 35 (2) ◽  
pp. 444-451 ◽  
Author(s):  
Dongmiao Zhao ◽  
Jun Tang ◽  
Xiuguang Wu ◽  
Changning Lin ◽  
Lijun Liu ◽  
...  
Keyword(s):  
Sediment Transport ◽  
Transport Model ◽  
Vof Method ◽  
Open Channels ◽  
Vertical Flow ◽  
Sediment Transport Model ◽  
Flow And Sediment Transport

Flow characteristics in open channels with aquatic rigid vegetation

2020 ◽  
Vol 32 (6) ◽  
pp. 1100-1108
Author(s):  
Yan-jie Wu ◽  
He-fang Jing ◽  
Chun-guang Li ◽  
Ying-ting Song
Keyword(s):  
Flow Characteristics ◽  
Open Channels ◽  
Rigid Vegetation

scholarly journals Sediment Transport and Water Flow Resistance in Alluvial River Channels: Modified Model of Transport of Non-Uniform Grain-Size Sediments

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2038
Author(s):  
Gennady Gladkov ◽  
Michał Habel ◽  
Zygmunt Babiński ◽  
Pakhom Belyakov
Keyword(s):  
Sediment Transport ◽  
Water Flow ◽  
Transport Model ◽  
Flow Characteristics ◽  
Field Measurements ◽  
Field Investigation ◽  
Empirical Modeling ◽  
River Channels ◽  
Channel Deformations ◽  
East European

The paper presents recommendations for using the results obtained in sediment transport simulation and modeling of channel deformations in rivers. This work relates to the issues of empirical modeling of the water flow characteristics in natural riverbeds with a movable bottom (alluvial channels) which are extremely complex. The study shows that in the simulation of sediment transport and calculation of channel deformations in the rivers, it is expedient to use the calculation dependences of Chézy’s coefficient for assessing the roughness of the bottom sediment mixture, or the dependences of the form based on the field investigation data. Three models are most commonly used and based on the original formulas of Meyer-Peter and Müller (1948), Einstein (1950) and van Rijn (1984). This work deals with assessing the hydraulic resistance of the channel and improving the river sediment transport model in a simulation of riverbed transformation on the basis of previous research to verify it based on 296 field measurements on the Central-East European lowland rivers. The performed test calculations show that the modified van Rijn formula gives the best results from all the considered variants.

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