On the Prediction of Sediment Transport in Sewers with Deposits

1993 ◽  
Vol 27 (5-6) ◽  
pp. 69-80 ◽  
Author(s):  
Rob A. Kleijwegt
Keyword(s):  
Sediment Transport ◽  
Probabilistic Models ◽  
Basic Knowledge ◽  
Incipient Motion ◽  
Negative Effects ◽  
Deterministic Models ◽  
Improve Design ◽  
Sewer Systems ◽  
Cohesive Sediment Transport ◽  
Bed Forms

There is a need for models to predict the negative effects of sewer deposits in order to improve design, maintenance and operation of sewerage systems. The lack of success of deterministic sewer sediment models in the past is caused by a lack of basic knowledge, which causes unknown uncertainties in the model's results. The basic knowledge about non-cohesive sediment transport has been studied with laboratory experiments. This has resulted in an understanding of the non-cohesive sewer sediment transport and the related subjects of bed shear stress, incipient motion, bed forms and flow resistance. This understanding can be used in the development of deterministic models for sewer systems. However, the next objective will be to develop probabilistic models.

Sewer Sediment Models and Basic Knowledge

1992 ◽  
Vol 25 (8) ◽  
pp. 123-130 ◽  
Author(s):  
R. A. Kleijwegt
Keyword(s):  
Sediment Transport ◽  
Water Level ◽  
Pipe Flow ◽  
Probabilistic Models ◽  
Transport Model ◽  
Field Research ◽  
Basic Knowledge ◽  
Laboratory Research ◽  
Sediment Transport Model

Sewer sediment models are being developed using results of laboratory and field research. The writer's laboratory research has given a good understanding of the basic processes that determine sediment transport in sewers. This understanding has resulted in a deterministic one-sewer sediment transport model. The results of calculations with the model show that the water level or energy slope and the sediment transport do not necessarily increase with increasing discharge. This is caused by the bed development and the transition to full-pipe flow. The basic knowledge can be used to develop deterministic or probabilistic models.

Modeling (partly) cohesive sediment transport in sewer systems

1996 ◽  
Vol 33 (9) ◽  
pp. 171-178 ◽  
Author(s):  
Jean E. Berlamont ◽  
Hilde M. Torfs
Keyword(s):  
Sediment Transport ◽  
Circular Cross Section ◽  
Flow Conditions ◽  
Transport Models ◽  
Rectangular Section ◽  
Sewer Systems ◽  
Cohesive Sediment Transport ◽  
The Many ◽  
Bed Material ◽  
Cohesive Bed

Although the basic mechanisms of sediment transport in sewers are the same as in rivers, it is not necessarily appropriate to use the many models that have been developed for sediment transport in rivers also in sewers. Different reasons are: 1) sewer sediments are often mixtures of cohesive and non cohesive material, and the bed is often stratified; 2) due to consolidation of the (partly cohesive) bed material, the erosion resistance of the bed may vary with time; 3) the flow conditions in sewers are usually unsteady, which is not accounted for in the classical sediment transport models; 4) existing models have been derived from experiments in rectangular flumes: the results are not directly applicable to sewers with circular cross section where the distribution of bed shear stress may be completely different from a rectangular section; 5) the limited availability of erodible material and the varying supply of sediments add additional difficulty to the modelling of sediment transport in sewers.

A Sediment Transport Model for Sewers

1992 ◽  
Vol 25 (8) ◽  
pp. 141-149
Author(s):  
O. Mark
Keyword(s):  
Sediment Transport ◽  
Transport Model ◽  
Hydrodynamic Description ◽  
Sewer Systems ◽  
Sediment Transport Model ◽  
Sediment Deposits ◽  
Bed Forms ◽  
Morphological Model ◽  
Technical University ◽  
The University

This paper describes a mathematical sediment transport model for sewers. The model consists of a full hydrodynamic description running in parallel with a morphological model. Four different sediment transport formulations have been implemented in the model. Fredsøe's method for the calculation of the resistance from bed forms is compared to experiments carried out at Chalmers Technical University, Sweden. The model can be used as a tool for the analysis of sewer systems with sediment deposits. The model is being developed as part of a study being carried out at the University of Aalborg, Denmark and VBB-VIAK, Sweden.

Principles and approaches for numerical modelling of sediment transport in sewers

1995 ◽  
Vol 31 (7) ◽  
pp. 107-115 ◽  
Author(s):  
Ole Mark ◽  
Cecilia Appelgren ◽  
Torben Larsen
Keyword(s):  
Mathematical Model ◽  
Sediment Transport ◽  
Numerical Modelling ◽  
Simple Application ◽  
Sewer Systems ◽  
Sediment Deposits ◽  
Model Mouse ◽  
Modelling Approaches

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.

Sediment transport under dry weather conditions in a small sewer system

1998 ◽  
Vol 37 (1) ◽  
pp. 155-162
Author(s):  
Flemming Schlütter ◽  
Kjeld Schaarup-Jensen
Keyword(s):  
Sediment Transport ◽  
Field Data ◽  
Field Measurements ◽  
Weather Conditions ◽  
Sewer System ◽  
Transport Models ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Initial Results

Increased knowledge of the processes which govern the transport of solids in sewers is necessary in order to develop more reliable and applicable sediment transport models for sewer systems. Proper validation of these are essential. For that purpose thorough field measurements are imperative. This paper renders initial results obtained in an ongoing case study of a Danish combined sewer system in Frejlev, a small town southwest of Aalborg, Denmark. Field data are presented concerning estimation of the sediment transport during dry weather. Finally, considerations on how to approach numerical modelling is made based on numerical simulations using MOUSE TRAP (DHI 1993).

NUMERICAL SIMULATION OF CURRENT INDUCED COHESIVE SEDIMENT TRANSPORT IN MINAMATA BAY

2018 ◽  
Vol 74 (5) ◽  
pp. I_943-I_948
Author(s):  
Changlu ZHOU ◽  
Akihide TADA ◽  
Shinichiro YANO ◽  
Akito MATSUYAMA ◽  
Changping CHEN
Keyword(s):  
Numerical Simulation ◽  
Sediment Transport ◽  
Cohesive Sediment ◽  
Cohesive Sediment Transport ◽  
Minamata Bay

scholarly journals A Computationally Efficient Shallow Water Model for Mixed Cohesive and Non-Cohesive Sediment Transport in the Yangtze Estuary

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1435
Author(s):  
Peng Hu ◽  
Junyu Tao ◽  
Aofei Ji ◽  
Wei Li ◽  
Zhiguo He
Keyword(s):  
Sediment Transport ◽  
Yangtze Estuary ◽  
Water Model ◽  
Cohesive Sediments ◽  
Shallow Water Model ◽  
Computationally Efficient ◽  
Time Step ◽  
The Yangtze Estuary ◽  
Erosion Coefficient ◽  
Cohesive Sediment Transport

In this paper, a computationally efficient shallow water model is developed for sediment transport in the Yangtze estuary by considering mixed cohesive and non-cohesive sediment transport. It is firstly shown that the model is capable of reproducing tidal-hydrodynamics in the estuarine region. Secondly, it is demonstrated that the observed temporal variation of suspended sediment concentration (SSC) for mixed cohesive and non-cohesive sediments can be well-captured by the model with calibrated parameters (i.e., critical shear stresses for erosion/deposition, erosion coefficient). Numerical comparative studies indicate that: (1) consideration of multiple sediment fraction (both cohesive and non-cohesive sediments) is important for accurate modeling of SSC in the Yangtze Estuary; (2) the critical shear stress and the erosion coefficient is shown to be site-dependent, for which intensive calibration may be required; and (3) the Deepwater Navigation Channel (DNC) project may lead to enhanced current velocity and thus reduced sediment deposition in the North Passage of the Yangtze Estuary. Finally, the implementation of the hybrid local time step/global maximum time step (LTS/GMaTS) (using LTS to update the hydro-sediment module but using GMaTS to update the morphodynamic module) can lead to a reduction of as high as 90% in the computational cost for the Yangtze Estuary. This advantage, along with its well-demonstrated quantitative accuracy, indicates that the present model should find wide applications in estuarine regions.

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