scholarly journals NUMERICAL STUDY ON SUSPENDED SEDIMENT TRANSPORT UNDER THE EFFECT OF WATER TEMPERATURE IN RESERVOIRS/LAKES

2021 ◽  
Vol 9 (3) ◽  
pp. 415-426
Author(s):  
Redvan GHASEMLOUNİA ◽  
Sedat KABDAŞLI
Keyword(s):  
Sediment Transport ◽  
Water Temperature ◽  
Suspended Sediment ◽  
Numerical Study ◽  
Suspended Sediment Transport ◽  
Effect Of Water

scholarly journals Numerical Study of Remote Sensed Dredging Impacts on the Suspended Sediment Transport in China’s Largest Freshwater Lake

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2449 ◽  
Author(s):  
Jianzhong Lu ◽  
Haijun Li ◽  
Xiaoling Chen ◽  
Dong Liang
Keyword(s):  
Remote Sensing ◽  
Sediment Transport ◽  
Suspended Sediment ◽  
Transport Model ◽  
Poyang Lake ◽  
Numerical Study ◽  
Point Sources ◽  
Freshwater Lake ◽  
Suspended Sediment Transport ◽  
Sediment Transport Model

As the largest freshwater lake in China, Poyang Lake plays an important role in the ecosystem of the Yangtze River watershed. The high suspended sediment concentration (SSC) has been an increasingly significant problem under the influence of extensive sand dredging. In this study, a hydrodynamic model integrated with the two-dimensional sediment transport model was built for Poyang Lake, considering sand dredging activities detected from satellite images. The sediment transport model was set with point sources of sand dredging, and fully calibrated and validated by observed hydrological data and remote sensing results. Simulations under different dredging intensities were implemented to investigate the impacts of the spatiotemporal variation of the SSC. The results indicated that areas significantly affected by sand dredging were located in the north of the lake and along the waterway, with a total affected area of about 730 km2, and this was one of the main factors causing high turbidity in the northern part of the lake. The SSC in the northern area increased, showing a spatial pattern in which the SSC varied from high to low from south to north along the main channel, which indicated close agreement with the results captured by remote sensing. In summary, this study quantified the influence of human induced activities on sediment transport for the lake aquatic ecosystem, which could help us to better understand the water quality and manage water resources.

A numerical study on suspended sediment transport in a partially vegetated channel flow

2021 ◽  
Vol 599 ◽  
pp. 126335
Author(s):  
Mingyang Wang ◽  
Eldad Avital ◽  
Qingsheng Chen ◽  
John Williams ◽  
Shuo Mi ◽  
...  
Keyword(s):  
Sediment Transport ◽  
Suspended Sediment ◽  
Channel Flow ◽  
Numerical Study ◽  
Suspended Sediment Transport

2D and 3D CFD Investigations of Seabed Shear Stresses Around Subsea Pipelines

2013 ◽  
Author(s):  
Wenwen Shen ◽  
Terry Griffiths ◽  
Mengmeng Xu ◽  
Jeremy Leggoe
Keyword(s):  
Sediment Transport ◽  
Suspended Sediment ◽  
Interaction Model ◽  
Suspended Sediment Transport ◽  
Shear Stresses ◽  
Parametric Function ◽  
Ample Evidence ◽  
North West ◽  
Wide Range ◽  
Subsea Pipelines

For well over a decade it has been widely recognised that existing models and tools for subsea pipeline stability design fail to account for the fact that seabed soils tend to become mobile well before the onset of pipeline instability. Despite ample evidence obtained from both laboratory and field observations that sediment mobility has a key role to play in understanding pipeline/soil interaction, no models have been presented previously which account for the tripartite interaction between the fluid and the pipe, the fluid and the soil, and the pipe and the soil. There are numerous well developed and widely used theories available to model pipe-fluid and pipe-soil interactions. A challenge lies in the way to develop a satisfactory fluid-soil interaction algorithm that has the potential for broad implementation under both ambient and extreme sea conditions due to the complexity of flow in the vicinity of a seabed pipeline or cable. A widely used relationship by Shields [1] links the bedload and suspended sediment transport to the seabed shear stresses. This paper presents details of computational fluid dynamics (CFD) research which has been undertaken to investigate the variation of seabed shear stresses around subsea pipelines as a parametric function of pipeline spanning/embedment, trench configuration and wave/current properties using the commercial RANS-based software ANSYS Fluent. The modelling work has been undertaken for a wide range of seabed geometries, including cases in 3D to evaluate the effects of finite span length, span depth and flow attack angle on shear stresses. These seabed shear stresses have been analysed and used as the basis for predicting sediment transport within the Pipe-Soil-Fluid (PSF) Interaction Model [2] in determining the suspended sediment concentration and the advection velocity in the vicinity of pipelines. The model has significant potential to be of use to operators who struggle with conventional stabilisation techniques for the pipelines, such as those which cross Australia’s North West Shelf, where shallow water depths, highly variable calcareous soils and extreme metocean conditions driven by frequent tropical cyclones result in the requirement for expensive and logistically challenging secondary stabilisation measures.

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