Daniel G. Wren

National Sedimentation Laboratory

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Roger A. Kuhnle

National Sedimentation Laboratory

Eddy J. Langendoen

National Sedimentation Laboratory

Yavuz Ozeren

University of Mississippi

James P. Chambers

The University of Texas at San Antonio

Wayne O. Carpenter

University of Mississippi

Bradley T. Goodwiller

University of Mississippi

James R. Rigby

United States Geological Survey

Tate O. McAlpin

U.S. Army Engineer Research and Development Center

Brian D. Barkdoll

Michigan Technological University

Keaton Jones

U.S. Army Engineer Research and Development Center

Cooperative Institutions

University of Mississippi

National Sedimentation Laboratory

Agricultural Research Service

United States Department of Agriculture

Carrier (United States)

United States Army Corps of Engineers

United States Geological Survey

University of Iowa

U.S. Army Engineer Research and Development Center

United States Army

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Effects of silt loading on turbulence and sand transport

International Journal of Sediment Research (2012)

Daniel G. Wren Roger A. Kuhnle

Silt

Flume

Reynolds stress

Suspended load

10.1016/s1001-6279(13)60004-9

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Citations (6)

Acoustic measurement of fines.

The Journal of the Acoustical Society of America (2009)

Wayne O. Carpenter Daniel G. Wren Roger A. Kuhnle James P. Chambers

The measurement of sediment particles <100 microns in diameter suspended in water has received little attention; however, particles of this size can account for a large fraction of the material transported in streams and rivers. In order to advance the current state of knowledge, the use of acoustic techniques as a surrogate measurement for the concentration of fine sediment particles in water is investigated. Both backscatter and attenuation will be evaluated as potential measurement techniques using a laboratory tank. Based on experience with the use of 1–5 MHz frequencies for backscatter measurements of particles in the 100–1000 micron size range, initial work will focus on the use of a frequency of approximately 20 MHz. The attenuation and backscatter due to a range of concentrations of bentonite and kaolinite will be reported.

Backscatter (email)

10.1121/1.4784587

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Field testing a High-Frequency acoustic attenuation system for measuring fine suspended sediments and algal movements

Applied Acoustics (2022)

Wayne O. Carpenter Bradley T. Goodwiller Daniel G. Wren Jason Taylor Jonathan AuBuchon

Diel vertical migration

Acoustic attenuation

10.1016/j.apacoust.2022.108980

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Citations (1)

Effect of Bimodal Gravel Size Distribution on the Clean-Out Depth of Sand

Journal of Hydraulic Engineering (2024)

Roger A. Kuhnle James E. Smith Daniel G. Wren Eddy J. Langendoen

10.1061/jhend8.hyeng-14188

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Field Techniques for Suspended-Sediment Measurement

Journal of Hydraulic Engineering (2000)

Daniel G. Wren Brian D. Barkdoll Roger A. Kuhnle Robert W. Derrow

The measurement of suspended sediment, particularly in field settings, is important in the documentation of sediment transport and deposition. Many measurement techniques have been used with varying degrees of success. The techniques, including their operating principles, advantages, and disadvantages are discussed. The techniques discussed include acoustic, bottle, pump, focused beam reflectance, laser diffraction, nuclear, optical backscatter, optical transmission, and spectral reflectance. Emphasis is placed on instrumentation techniques, as this is the area of suspended-sediment measurement that has the greatest potential for improving sediment data. Acoustic technology (if further developed) emerges as a promising technology because of its ability to measure the concentration profile without intruding into the flow. This technology-transfer information will be valuable to practitioners and researchers needing to choose a means of measuring suspended sediment. The choice of a measurement technique has implications for sampling efficacy and expense.

Instrumentation

Backscatter (email)

Deposition

10.1061/(asce)0733-9429(2000)126:2(97)

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Citations (143)

Simulated Prediction of Wave-Induced Morphological Change of a Model Sand Embankment Using XBeach in the Single Layer, Non-hydrostatic Mode (Room 322, Tuesday June 27th, 2:00pm-3:30pm)

William Rossell Yavuz Ozeren Daniel G. Wren

Hydrostatic equilibrium

Mode (computer interface)

Hydrostatic pressure

10.26226/m.64429f3ac680fa2666996cb5

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Variability in Suspended-Sediment Concentration over Mobile Sand Beds

Journal of Hydraulic Engineering (2005)

Daniel G. Wren Sean J. Bennett Brian D. Barkdoll Roger A. Kuhnle

Lateral and longitudinal variability in suspended-sediment concentration was investigated over dune and upper-regime plane beds under steady, uniform flow in a laboratory flume. A much greater sampling time was required to reliably predict mean concentration in a dune bed than for an upper-regime plane bed. Laterally separated, simultaneous samples over both dune and upper-regime plane beds were poorly correlated.

Flume

Bedform

10.1061/(asce)0733-9429(2005)131:8(733)

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Citations (5)

Turbulent Flow and Sand Transport over a Cobble Bed in a Laboratory Flume

Journal of Hydraulic Engineering (2013)

Daniel G. Wren Roger A. Kuhnle Eddy J. Langendoen James R. Rigby

Improving the prediction of sand transport downstream of dams requires characterization of the interaction between turbulent flow and near-surface interstitial sands. The advanced age and impending decommissioning of many dams have brought increased attention to the fate of sediments stored in reservoirs. Sands can be reintroduced to coarse substrates that have available pore space resulting from periods of sediment-starved flow. The roughness and porosity of the coarse substrate are both affected by sand elevation relative to the coarse substrate; therefore, the turbulence characteristics and sediment transport over and through these beds are significantly altered after sediment is reintroduced. Past work by the writers on flow over sand-filled gravel beds revealed that the fine-sediment level controls the volume of material available for transport and the area of sediment exposed to the flow. The present work expands on the gravel-bed experiments by conducting similar measurements of turbulent flow and sand transport over a bed of cobbles with a median diameter of approximately 150 mm. This change in scale expands the generality of the previous experiments and broadens the range of sand transport and turbulence measurements. It was found that the same relationship between bed shear stress and sand elevation was valid for both gravel and cobble systems. Reductions in bed shear stress, relative to the clear-water case, were observed as the sand elevation was increased, although the highest sand elevation did not yield the lowest shear stress. Quadrant analysis showed that, for stronger turbulent events, there was an increase of sweeps and a decrease in bursts as the sand level was raised. This effect was observed for a region with a height of approximately 1.4 times the thickness of the roughness layer.

Flume

Cobble

Flow conditions

10.1061/(asce)hy.1943-7900.0000838

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Citations (18)

Utilizing acoustic suspended-sediment measurement techniques in laboratory flumes

The Journal of the Acoustical Society of America (2002)

Daniel G. Wren Srikanth Vadakapurapu James P. Chambers Roger A. Kuhnle Brian D. Barkdoll

Automated measurement of suspended sediments is crucial to the study of sediment transport. The short duration, high-intensity flows that are responsible for a large fraction of sediment movement are best observed by continuous monitoring systems. Acoustic systems are ideal for continuous monitoring and add the advantage of nonintrusively measuring through the water column. In the present work, a single-frequency acoustic system for measuring suspended-sediment concentration in fluvial environments is described. The equipment and procedures used in developing hardware and software for the acoustic technique in two sets of laboratory flume experiments will be presented. Both implicit and explicit methods were used to convert backscatter data into sediment concentrations. The implicit method yielded 39% error and the explicit, 20%.

Flume

Backscatter (email)

10.1121/1.4779407

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Uncertainty for the ISSDOTv2 Bedload Measurement Method

Journal of Hydraulic Engineering (2023)

Tate O. McAlpin Daniel G. Wren Keaton Jones David Abraham Roger A. Kuhnle

The Integrated, Section Surface Difference Over Time, version 2 (ISSDOTv2) method provides a means of quantifying bedload in large sandbed rivers. Like all measurements, it is important to understand the uncertainty associated with the method before making management decisions based on its results. A methodology is presented for quantifying and combining the uncertainty for each component of the ISSDOTv2 method including particle density, bed porosity, acoustically measured bed topography, the timing of measurements, sand wave identification, and regression analysis used for geometric correction of bedload measurements. The approach provides an indication of the relative magnitude of each source of uncertainty in addition to the uncertainty in the final resultant transport rate. Laboratory flume measurements were used to evaluate the uncertainty limits and verify the approach. The greatest contributor to uncertainty was found to be the bathymetric uncertainty, and, at the highest transport rates, cumulative relative uncertainty was found to be approximately 10%. Cumulative relative uncertainties grew rapidly with decreasing flow rates, driven primarily by the higher relative contribution of the effect of bathymetric uncertainty on the smaller bedforms that are typically present at lower transport rates. The approach documented here will be transferrable to real-world systems to determine the uncertainty in measured bedload sediment transport rates using the ISSDOTv2 method.

Flume

Bedform

Uncertainty Quantification

10.1061/jhend8.hyeng-13505

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Citations (1)