Results 171 to 180 of about 774 (212)

Critical Bed Shear Stress for Unisize Sediment

Journal of Hydraulic Engineering, 2006
The overall, spatially averaged, mean magnitude of local, spatially averaged (over a small area enclosing the particles' projected area), instantaneous, critical Shields shear-stress parameters required for incipient motion of uniform-sized sand grains, independent of the bed shear-velocity particle Reynolds number, equal to 0.16, is obtained from ...
Oscar A. Sarmiento, Marco A. Falcon
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Bed shear stress in non-uniform flow

Environmental Fluid Mechanics, 2016
Bed shear stress is an essential parameter in the description of flow motion and sediment transport. Several methods have been proposed to estimate bed shear stress under uniform flow conditions, yet few are applicable to non-uniform flow. A new approach is proposed to compute bed shear stress for non-uniform flow.
Xiao-Feng Zhang, Wen-Ting Yang, Jun-Qiang Xia   +2 more
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Mobile‐Bed Friction at High Shear Stress

Journal of Hydraulic Engineering, 1989
Analysis demonstrates, and experiments confirm that the frictional behavior of mobile beds at high shear stress is inherently different from either of the two classical cases—smooth wall and rough wall. For those two cases, the characteristic lengths for friction are based on viscosity and grain size, respectively.
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The Bed Shear Stress of an Annular Sea-Bed Flume

1990
An accurate estimation of erosion and deposition rates is very important in the study of fine, cohesive sediment transport. In. situ sea-bed flume tests would be the most reliable way to obtain these rates. Young and Southard (1978) used a sea-bed flume to study the incipient motion of sandy sediments.
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Bed shear stresses and the sedimentation of sandy gravels

Marine Geology, 1972
Abstract It is suggested that variations in bed shear stress between the crests and troughs of gravel waves may be the cause of simultaneous deposition of sand and gravel and, coupled with spatial variations in gravel wave steepness, can produce variations in the proportions of sand and gravel in the seabed sediment.
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Numerical Modelling of Bed Shear Stress in OpenFOAM

2019
In coastal zones, erosion is the major threat to the livelihood as it leads to the water inundation into the human premises. Sediment transport results in erosions causes morphological changes and also affects the coastal ecosystem. The sediment transport processes are primarily driven by bed shear stress induced by waves and currents.
Nandakumar Visuvamithiran, V. Sriram, Jaya Kumar Seelam   +2 more
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Improvements on bed‐shear stress formulation for pier scour computation

International Journal for Numerical Methods in Fluids, 2011
AbstractThis paper introduces an improved formula for the bed‐shear stress by applying the vorticity effect and its application in a 3D flow and sediment model to estimate scouring around bridge piers. Up to now, the sediment transport formulae used for computing pier scour were developed based on the general scouring in unobstructed flow.
Abbasnia, Amir Hosein, Ghiassi, Reza
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Computation of Bed Shear Stress from Velocity Measurements in a Gradually Varying Roughness Bed

38th IAHR World Congress - "Water: Connecting the World", 2019
An experimental study was conducted in a gradually varied roughness bed by using a Particle Image Velocimetry (PIV) system. The local bed shear stress was evaluated from four distinct methods: the log-law, the Reynolds shear stress (RSS), the vertical turbulence intensity and the turbulent kinetic energy (TKE) methods.
Vijit RATHORE, Nadia PENNA, Subhasish DEY, Roberto GAUDIO   +3 more
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Measuring bed shear stress along vegetated river beds using FST-hemispheres

Journal of Environmental Management, 2008
The measurement of the bed shear stress along vegetated river beds is essential for accurately predicting the water level, velocity and solute and sediment transport fluxes in computational hydroenvironmental models. Details are given herein of an experimental and theoretical study to determine the bed boundary shear stress along vegetated river beds ...
B N, Bockelmann-Evans, R, Davies, R A, Falconer   +2 more
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Bed-Load Transport at High Shear Stress

Journal of the Hydraulics Division, 1966
High bed shear stresses can be obtained if pressurized conduits are used, and the results of such experimentation are presented herein. In this range existing transport equations diverge rapidly, and the present work indicates that for sand the Einstein bed-load function is not applicable at high shear stress.
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