scholarly journals Swash zone boundary conditions and direct bed shear stress measurements over loose sediment beds

2015 ◽  
Author(s):  
Zhonglian Jiang
Keyword(s):  
Shear Stress ◽  
Boundary Conditions ◽  
Bed Shear Stress ◽  
Swash Zone ◽  
Zone Boundary ◽  
Stress Measurements ◽  
Loose Sediment

Bed shear stress measurements for vims Sea Carousel

1995 ◽  
Vol 129 (1-2) ◽  
pp. 129-136 ◽  
Author(s):  
Jerome P.-Y. Maa ◽  
C.-H. Lee ◽  
F.J. Chen
Keyword(s):  
Shear Stress ◽  
Bed Shear Stress ◽  
Stress Measurements

Swash zone boundary conditions for long-wave models

2005 ◽  
Vol 52 (10-11) ◽  
pp. 971-976 ◽  
Author(s):  
Giorgio Bellotti ◽  
Maurizio Brocchini
Keyword(s):  
Boundary Conditions ◽  
Swash Zone ◽  
Zone Boundary ◽  
Long Wave ◽  
Wave Models

scholarly journals Direct bed shear stress measurements in bore-driven swash

2009 ◽  
Vol 56 (8) ◽  
pp. 853-867 ◽  
Author(s):  
M.P. Barnes ◽  
T. O'Donoghue ◽  
J.M. Alsina ◽  
T.E. Baldock
Keyword(s):  
Shear Stress ◽  
Bed Shear Stress ◽  
Stress Measurements

An affordable and reliable device for direct bed shear stress measurements

2021 ◽  
Author(s):  
Stephan Niewerth ◽  
Francisco Núñez-González ◽  
Toni Llull
Keyword(s):  
Shear Stress ◽  
Low Cost ◽  
Large Degree ◽  
Bed Shear Stress ◽  
Flow Conditions ◽  
Stress Measurements ◽  
Boundary Shear ◽  
Shear Plate ◽  
Wide Range ◽  
Boundary Shear Stress

<p>The entrainment and transport of sediment by hydrodynamic mechanisms is strongly related to bed shear stress exerted by flow. Therefore, to quantify sediment transport and to determine sediment incipient motion conditions, accurate estimations of bed shear stress are required. Most of the existing methods used in hydraulics and river engineering to determine bed shear stress are indirect, and are mostly restricted to limited flow conditions or contain a large degree of uncertainty. Although devices to perform direct measurements of boundary shear stress exist, they are normally based on expensive technology. We developed a shear plate for direct shear stress measurements, using relatively low cost components. In this work we present preliminary results of measurements performed with the new shear plate, to characterize the bottom shear stress generated by a ship propeller. The data result in the expected quadratic relation between bed shear stress and jet velocities, and also give evidence of a good reproducibility. We show that the new shear plate appears to be a promising device for reliable measurements of submerged boundary shear stress under a wide range of environments and flow conditions.</p>

The swash of solitary waves on a plane beach: flow evolution, bed shear stress and run-up

2015 ◽  
Vol 779 ◽  
pp. 556-597 ◽  
Author(s):  
Nimish Pujara ◽  
Philip L.-F. Liu ◽  
Harry Yeh
Keyword(s):  
Shear Stress ◽  
Solitary Waves ◽  
Large Scale ◽  
Breaking Waves ◽  
Shear Stresses ◽  
Bed Shear Stress ◽  
Swash Zone ◽  
Flow Evolution ◽  
Run Up ◽  
Bed Shear Stresses

The swash of solitary waves on a plane beach is studied using large-scale experiments. Ten wave cases are examined which range from non-breaking waves to plunging breakers. The focus of this study is on the influence of breaker type on flow evolution, spatiotemporal variations of bed shear stresses and run-up. Measurements are made of the local water depths, flow velocities and bed shear stresses (using a shear plate sensor) at various locations in the swash zone. The bed shear stress is significant near the tip of the swash during uprush and in the shallow flow during the later stages of downrush. In between, the flow evolution is dominated by gravity and follows an explicit solution to the nonlinear shallow water equations, i.e. the flow due to a dam break on a slope. The controlling scale of the flow evolution is the initial velocity of the shoreline immediately following waveform collapse, which can be predicted by measurements of wave height prior to breaking, but also shows an additional dependence on breaker type. The maximum onshore-directed bed shear stress increases significantly onshore of the stillwater shoreline for non-breaking waves and onshore of the waveform collapse point for breaking waves. A new normalization for the bed shear stress which uses the initial shoreline velocity is presented. Under this normalization, the variation of the maximum magnitudes of the bed shear stress with distance along the beach, which is normalized using the run-up, follows the same trend for different breaker types. For the uprush, the maximum dimensionless bed shear stress is approximately 0.01, whereas for the downrush, it is approximately 0.002.

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