Numerical modelling of sediment transport in a channel bend with floating units

Author(s):  
Diwash Lal Maskey ◽  
Nils Ruther

<p>Floating units/booms are used to trap or guide floating debris in watercourses. In a relatively shallow depth, these floats could affect the velocity distribution, sediment transport and channel bed deformation.  A three-dimensional non-hydrostatic numerical modelling was performed in a 180 degree channel bend with floats to see the effects in flow distribution and bed deformation as a conceptual study. Different configurations of the floats were simulated. The results showed that the flow velocity increased and deposition decreased at the inner bank of the bend. Use of floating units could be studied to alter sediment deposition pattern and sediment transport phenomenon in watercourses.</p>

2009 ◽  
Vol 47 (5) ◽  
pp. 670-675 ◽  
Author(s):  
Tim Fischer-Antze ◽  
Nils Rüther ◽  
Nils R.B. Olsen ◽  
Dieter Gutknecht

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1779
Author(s):  
Keivan Kaveh ◽  
Markus Reisenbüchler ◽  
Sandip Lamichhane ◽  
Tobias Liepert ◽  
Ngoc Dung Nguyen ◽  
...  

In recent decades, a variety of morphodynamic model systems have been developed to improve our understanding of sediment transport and the resulting changes in riverbed topography. Despite progress in the description of physical processes, the degree of accuracy of morphodynamic model results remains difficult to assess and are also less than for hydrodynamics alone. In this paper, three different 2D morphodynamic systems have been applied to simulate a complex hydrodynamic and morphodynamic situation. These model systems were validated using data of sediment sorting and bed deformation conducted in a 180° channel bend under unsteady-flow conditions. The calculations obtained by each modeling system were compared with the available observed data. The simulated results showed that all applied morphodynamic models could precisely calculate the bed level changes and the areas of deposition and scour. However, the models are not efficient enough to predict the distribution of the mean grain size in the channel bend.


2007 ◽  
Vol 34 (9) ◽  
pp. 1087-1095 ◽  
Author(s):  
B Minor ◽  
C D Rennie ◽  
R D Townsend

A three-dimensional numerical model was used to examine the turbulent flow field and associated sediment transport due to a series of barbs (submerged groynes) in a channel bend. Model results were in good agreement with measured laboratory data and adequately simulated the important features of sediment transport. Statistical comparison of the predicted and measured equilibrium bed geometry found average regression coefficients of determination of 0.77 and 0.72 for the 90° and 135° channels, respectively. The predicted velocity data followed expected trends. The capability of a three-dimensional numerical model to simulate sediment transport through bend sections of a channel containing barbs was verified. This included the simulation of the effects of different arrangements of barb groups and an analysis of the data to determine the relation of the flow field to associated scour and deposition in a complex fluvial environment. These novel results are useful for improved analyses of the bank-protection capabilities of these structures and for the development and improvement of design guidelines.Key words: three-dimensional models, numerical models, movable bed models, channel bends, turbulence, secondary flow, scour, barbs, groynes.


1995 ◽  
Vol 31 (7) ◽  
pp. 107-115 ◽  
Author(s):  
Ole Mark ◽  
Cecilia Appelgren ◽  
Torben Larsen

A study has been carried out with the objectives of describing the effect of sediment deposits on the hydraulic capacity of sewer systems and to investigate the sediment transport in sewer systems. A result of the study is a mathematical model MOUSE ST which describes sediment transport in sewers. This paper discusses the applicability and the limitations of various modelling approaches and sediment transport formulations in MOUSE ST. Further, the paper presents a simple application of MOUSE ST to the Rya catchment in Gothenburg, Sweden.


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