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潮汐通道水动力和泥沙的湍参数化效应:南海北部崖门水道

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哈尔滨工程大学学报（英文版） 2023年第2期22卷 284-295页

作者：杨一刘金贵李谊纯张春华 Haikou Marine Environment Monitoring Station State Oceanic AdministrationHaikou 570000China College of Ocean and Meteorology Guangdong Ocean UniversityZhanjiang 524088China Key Laboratory of Harbour Coastal and Offshore EngineeringBeibu Gulf UniversityQinzhou 535011China

In this study,we conducted numerical experiments to examine the effects of turbulence parameterization on temporal and spatial variations of suspended sediment ***,we applied the numerical model to the Yamen Channel,one of the main eight outfalls in the Pearl River *** the field application,we implemented the k−εscheme with a reasonable stability function using the continuous deposition formula during the erosion process near the water-sediment *** further validated and analyzed the temporal-spatial suspended sediment concentrations(SSCs).The experimental results show that under specified initial and boundary conditions,turbulence parameterization with stability functions can lead to different vertical profiles of the velocity and *** k−εpredicts stronger mixing with a maximum value of approximately twice the k−*** k−kl results in smaller SSCs near the surface layer and a larger vertical gradient than the k−ε.In the Yamen Channel,though the turbulent dissipation,turbulent viscosity and turbulence kinetic energy exhibit similar trends,SSCs differ significantly between those at low water and high water due to the tidal asymmetry and settling lag *** results can provide significant insights into environmental protection and estuarine management in the Pearl River Delta.

关键词： suspended sediment General ocean turbulence model(GOTM) Turbulence parameterization Yamen Channel Finite volume community ocean model(FVCOM)

Stochastic particle based models for suspended particle movement in surface flows

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International Journal of sediment Research 2014年第2期29卷 195-207页

作者： Christina W.TSAI Chuanjian MAN Jungsun OH Department of Civil Structural and Environmental EngineeringState University of New York at BuffaloBuffaloNY 14051USA Assoc.Prof. Department of Civil and Environmental Engineering National Taiwan University

Modeling of suspended sediment particle movement in surface water can be achieved by stochastic particle tracking model *** this paper,different mathematical forms of particle tracking models are introduced to describe particle movement under various flow conditions,i.e.,the stochastic diffusion process,stochastic jump process,and stochastic jump diffusion *** the stochastic diffusion process can be used to represent the stochastic movement of suspended particles in turbulent flows,the stochastic jump and the stochastic jump diffusion processes can be used to describe suspended particle movement in the occurrences of a sequence of extreme *** extreme flow herein is defined as a hydrologic flow event or a hydrodynamic flow phenomenon with a low probability of occurrence and a high impact on its ambient flow *** this paper,the suspended sediment particle is assumed to immediately follow the extreme flows in the jump process(*** time lag between the flow particle and the sediment particle in extreme flows is considered negligible).In the proposed particle tracking models,a random term mainly caused by fluid eddy motions is modeled as a Wiener process,while the random occurrences of a sequence of extreme flows can be modeled as a Poisson *** frequency of occurrence of the extreme flows in the proposed particle tracking model can be explicitly accounted for by the Poisson process when evaluating particle *** ensemble mean and variance of particle trajectory can be obtained from the proposed stochastic models via *** ensemble mean and variance of particle velocity are verified with available *** of the proposed stochastic particle tracking models for sediment transport modeling is also discussed.

关键词： suspended sediment Particle tracking model Stochastic modeling Diffusion process Poisson jump process Jump diffusion process Extreme flows

Stream turbidity responses to storm events in a pristine rainforest watershed on the Coral Coast of southern Fiji

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International Journal of sediment Research 2016年第4期31卷 279-290页

作者： Arishma R.Ram James P.Terry School of Environment The University of Auckland College of Sustainabiliry Sciences Zayed University

On the Coral Coast of Viti Levu Island in Fiji,inadequate knowledge of suspended sediment delivery patterns in small pristine coastal watersheds hinders any future assessment of accelerated erosion in disturbed areas *** study adopts a rainfall-stream turbidity monitoring approach in the Votua Creek,which drains a small,steep but minimally-disturbed coastal rainforest *** rainfall characteristics,stream depth and water turbidity were continuously monitored over one complete Fiji wet season from October 2009 to April *** aim was to evaluate whether these parameters provide sufficient information to illustrate basic features of storm-sediment transport responses,in the case of limited stream gauging and very simple sediment rating *** is important because Pacific Island nations like Fiji do not have the resources to initiate long-term gauging and sediment sampling programmes across numerous small catchments.A significant power function demonstrates that turbidity(T) is a suitable proxy for total suspended solids(ISS) for turbidity measurements above 5 NTU,with TSS=0.930T1.111(r= 0.98,Psediment responses to major ***-based analysis revealed that negative(anticlockwise) hysteresis is a typical flow-turbidity pattern for STR *** hysteresis is produced when secondary episodes of renewed(heavy) rainfall occur after maximum intensity,in the later phase of storm *** Cyclo

关键词： Coastal watersheds Fiji Storm events Stream turbidity suspended sediment Negative hysteresis

sedimentation model and analysis for differential settling of two-particle-size suspensions in the Stokes region

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International Journal of sediment Research 2010年第2期25卷 119-133页

作者： P. KRISHNAMOORTHY Department of Chemistry.Arignar Anna Government Arts College

A model is developed for predicting the settling velocity in suspensions of particles of two different sizes based on experimental data for the settling rate of two-size suspensions in various liquids using particles of equal density. In these experiments, the retarding effect of the smaller particles on the settling velocities of the larger ones is taken into account. The model considers Steinour’s fundamental equation and assumes a fixed arrangement of particles and constant velocity in a single-size suspension under creeping flow conditions and the flow spaces changing in shape and size with the volumetric concentration of solids. Based on the foregoing, a simplified model equation is proposed for the settling of particles in a suspension as a function of their free fall velocity and of the solids concentration. Different experimental conditions are used to show the effect of solids concentration, liquid density, and viscosity on the settling behaviour of the glass beads with low particle Reynolds numbers and bed porosity ranging from 0.62 to 0.95. The present study involves the lower and upper interface velocities of two-size suspensions of solids in liquids (concentrated and dilute suspensions) covering a wide range in the properties of the liquids and solids, and more specifically in solids concentration (Glass beads and Sand).

关键词： Settling velocity suspended sediment Fluid properties Solid concentration

Variation of turbidity during subsurface abstraction of river water: A case study

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International Journal of sediment Research 2010年第4期25卷 355-365页

作者： A.K.THAKUR C.S.P.OJHA Department of Science and Technology Patna India Department of Civil Engineering IIT Roorkee Uttarakhand 247667 India

Rivers are known to carry sediment loads. Many rivers in Asia including Kosi, Brahmaputra, Bagmati rivers in India and Yellow and Yarlung Tsangpo rivers in China are well known for their carriage of excessive sediment loads. In India, many water abstraction units are located along river banks. Their success depends on how the sediment load is trapped as the sediment laden water flows towards the pumping wells located few hundred meters away from river bank. In this work, based on the analysis of a data of one year on suspended load variations in a canal, located at Haridwar, India, trap efficiency variations are studied during the passage of source water to the abstraction well. Considering the subsurface basin, located within the source water and the abstraction well, as a hypothetical settling basin, variation of trap efficiency is related with the influent concentration. It is observed that the trap efficiency depends on the influent concentration. Appropriate functional forms for the variation of trap efficiency with the influent concentrations are also identified.

关键词： Turbidity River bank filtration suspended sediment Bank filtrate Clogging Influent concentration and effluent concentration Trap efficiency

sediment DAMAGES AND RECENT TRENDSIN THE UNITED STATES

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International Journal of sediment Research 2000年第2期15卷 135-148页

作者： Jerry M. Bernard (National Geologist) Thomas A. Iivari(Senior Hydrologist, United States Department of Agriculture-Natura ResourcesConservation Service, Washington, DC) United States Dept. of Agriculture Nat. Resources Conservation Service Washington DC United States

In the United States, cropland erosion has decreased by an estimated one billion tons or 42 Percent for the period 1982 to 1997 (USDA NRCS, 1998) through erosion reduction provisions of the Food Security Actof 1985 and the ongoing soil conservation programs administered by the United States Department ofAgriculture’s Soil Conservation Service (USDA-SCS), which became the Natural Resources ConservationService (USDA-NRCS) in *** U.S. Geological Survey has measured suspended sediment loads at strearn gages from 198O through1989 and showed primarily decreases of from 1 to 12 percent for most regions and increases for only threeregions, ranging from 2 to l2 percent.A Reservoir sediment Information System (RESIS) was created so that decades of dare on reservoir sediment deposits could be evaluated (Atwood, 1994, Steffen, 1994; Atwood and Steffen, 1994). Theresults of analyses show a major increase in unit-area sediment deposition rates during the period 1970through 1985, which may be attributable to increased cropland acreage, a switch from diversified farming tointensive monocultUred crops, with widespread adoption of soybeans. The most recent measured ratesshow that 25 percent of the United States reservoirs would be at least half-filled with sediment by 2O18,although there is a significant data gap since 1985. Relatively few reservoirs were surveyed since 1985 dueto lack of funding priority and increased survey labor costs.

关键词： Cropland erosion Soil conservation program suspended sediment Reservoir sediment information system

Measurements of coupled fluid and sediment motion over mobile sand dunes in a laboratory flume

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International Journal of sediment Research 2008年第4期23卷 329-337页

作者： Daniel G.WREN Roger A.KUHNLE Research Hydraulic Engineer USD A-ARS-National Sedimentation LaboratoryPh.D Research Hydraulic Engineer USD A-ARS-National Sedimentation Laboratory

The relationship between turbulent fluid motions and sediment particle motions over mobile sand dunes was investigated by using a laser Doppler velocimeter and an acoustic backscatter system in laboratory experiments performed at the USDA-ARS-National sedimentation Laboratory. Profiles of acoustic backscatter from particles and at-a-point turbulence data were collected while translating both measurement devices downstream at the speed of mobile dune bedforms. The resulting data set was used to examine the frequency (recurrence frequency) at which the fluctuating backscatter and fluid velocity signals exceeded magnitude thresholds based on the standard deviation (σ) of the local velocity and the magnitude the acoustic signal resulting from backscatter from suspended particles. The slope of the downstream and vertical velocity recurrence frequencies generally indicated a gradually increasing recurrence time with increasing elevation. The recurrence frequency for acoustic backscatter data was not strongly variable with elevation. The closest correspondence between the recurrence frequencies of sediment backscatter and vertical velocities at the 1σ magnitude threshold was in a region defined by X/L<0.4 and y<6 cm. The downstream velocity was most closely related to backscatter in a small region at 0.4

关键词： Turbulence suspended sediment Acoustic backscatter Dunes

Experimental and numerical modelling of sedimentation in a rectangular shallow basin

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International Journal of sediment Research 2008年第3期23卷 212-232页

作者： Sameh A. KANTOUSH Erik BOLLAERT Anton J. SCHLEISS Ecole Polytechnique Fédérale de Lausanne (EPFL) Laboratory of Hydraulic Constructions (LCH) Station 18 CH -1015 Lausanne SwitzerlandDr. Ecole Polytechnique Fédérale de Lausanne (EPFL) Laboratory of Hydraulic Constructions (LCH) Station 18 CH -1015 Lausanne SwitzerlandProf.

Numerical simulation of flows in shallow reservoirs has to be checked for its consistency in predicting real flow conditions and sedimentation patterns. Typical flow patterns may exhibit flow separation at the inlet, accompanied by several recirculation and stagnation areas all over the reservoir surface. The aim of the present research project is to study the influence of the geometry of a reservoir on sediment transport and deposition numerically and experimentally, focusing on a prototype reservoir depth between 5 and 15 m as well as suspended sediment transport. A series of numerical simulations is presented and compared with scaled laboratory experiments, with the objective of testing the sensitivity to different flow and sediment parameters and different turbulence closure schemes. Different scenarios are analyzed and a detailed comparison of preliminary laboratory tests and some selected simulations are presented. The laboratory experiments show that suspended sediment transport and deposition are determined by the initial flow pattern and by the upstream and downstream boundary conditions. In the experiments, deposition in the rectangular basin systematically developed along the left bank, although inflow and outflow were positioned symmetrically along the centre of the basin. Three major horizontal eddies developed influencing the sediment deposition pattern. Although asymmetric flow patterns are privileged, a symmetric pattern can appear from time to time. This particular behaviour could also be reproduced by a two-dimensional depth-averaged flow and sediment transport model (CCHE2D). The paper presents numerical simulations using different turbulence closure schemes (k-ε and eddy viscosity models). In spite of the symmetric setup, these generally produced an asymmetric flow pattern that can easily switch sides depending on the assumptions made for the initial and boundary conditions. When using the laboratory experiment as a reference, the most reliable n

关键词： Shallow reservoir sedimentation and morphology suspended sediment Reservoir geometry influence Numerical simulations Scaled physical modelling

Currents induced by vertical varied radiation stress in standing waves and evolution of the bed composed of fine sediments

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International Journal of sediment Research 2009年第2期24卷 214-226页

作者： Jing-Xin ZHANG1 and Hua LIU21 Lecturer,Department of Engineering Mechanics,School of Naval Architecture,Ocean and Civil Engineering,Shanghai Jiao Tong University,800 Dongchuan Road,Shanghai 200240,China 2 Department of Engineering Mechanics,School of Naval Architecture,Ocean and Civil Engineering,Shanghai Jiao Tong University,800 Dongchuan Road,Shanghai 200240,China Department of Engineering Mechanics School of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong University 800 Dongchuan Road Shanghai 200240 China

This paper extends the conventional concept of radiation stress(Longuet-Higgins and Stewart,1964) in progressive water waves to standing waves,so that its vertical profile could be defined and calculated in a new technical way. The hydrodynamic numerical model being coupled with the vertically varying radiation stress in standing waves is used to simulate the currents being induced by standing waves in the vertical section. Numerical modeling of suspended sediment transport is then carried out to simulate the evolution of the bed composed of fine sediments by the currents. The scour and deposition patterns simulated are in qualitative agreement with prior laboratory and field observations.

关键词： Standing wave Vertical variation in radiation stress Scour pattern suspended sediment