scholarly journals Laboratory Experiments for Wave-Driven Sand Transport Prediction

10.3990/2.171 ◽  
2012 ◽  
Author(s):  
T. O'Donoghue ◽  
D.A. van der A
Keyword(s):  
Laboratory Experiments ◽  
Sand Transport ◽  
Transport Prediction

scholarly journals SHEETFLOW SEDIMENT TRANSPORT UNDER SKEWED - ASYMMETRIC WAVES AND CURRENTS

2012 ◽  
Vol 1 (33) ◽  
pp. 50 ◽  
Author(s):  
Le Phuong Dong ◽  
Shinji Sato
Keyword(s):  
Sediment Transport ◽  
Laboratory Experiments ◽  
Fine Sand ◽  
Sand Transport ◽  
Phase Lag ◽  
Half Cycle ◽  
Experimental Conditions ◽  
Wide Range ◽  
Waves And Currents ◽  
Asymmetric Flows

Prototype scale laboratory experiments have been conducted to investigate the sheetflow sediment transport of uniform sands under different skewed-asymmetric oscillatory flows. Experimental results reveal that in most of the case with fine sand, the “cancelling effect”, which balances the on-/off-shore net transport under pure asymmetric/skewed flows and results a moderate net transport, was developed for combined skewed-asymmetric flow. However, under some certain conditions (T > 5s) with coarse sands, the onshore sediment transport was enhanced by 50% under combined skewed-asymmetric flows. Sand transport mechanism under oscillatory sheetflow conditions is also studied by comparing the maximum bed shear stress and the phase lag parameter at each half cycle. A comparison of measurements including the new experimental data with a number of practical sand transport formulations shows that the Dong et al. (2013) formulation performs the best in predicting the measured net transport rates over a wide range of experimental conditions

scholarly journals A MODEL FOR BREACH GROWTH IN A DIKE-BURST

1988 ◽  
Vol 1 (21) ◽  
pp. 140 ◽  
Author(s):  
Paul J. Visser
Keyword(s):  
Mathematical Model ◽  
The Netherlands ◽  
Laboratory Experiments ◽  
Suspended Load ◽  
Experimental Results ◽  
Sand Transport ◽  
Model Predictions ◽  
Pumped Storage

A mathematical model for sand-dike breach erosion is presented. The heart of the model is a modified Bagnold (1963) energetics—based sand transport conception combined with a simplified Galappatti and Vreugdenhil (1985) pick up mechanism for the suspended load. The model has been tested to three laboratory experiments. The agreement between model predictions and experimental results is surprisingly good. Prototype calculations are presented for the 73 m high sand—dike of a proposed pumped—storage plant in the Netherlands.

Towards a process-based model to predict dune erosion along the Dutch Wadden coast

2012 ◽  
Vol 91 (3) ◽  
pp. 357-372 ◽  
Author(s):  
B.G. Ruessink ◽  
M. Boers ◽  
P.F.C. van Geer ◽  
A.T.M. de Bakker ◽  
A. Pieterse ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Current Knowledge ◽  
Numerical Models ◽  
Field Studies ◽  
Breaking Waves ◽  
Sand Transport ◽  
Breaking Wave ◽  
Field Observations ◽  
Erosion Model ◽  
Dune Erosion

AbstractAn equilibrium dune-erosion model is used every six years to assess the capability of the most seaward dune row on the Dutch Wadden islands to withstand a storm with a 1 in 10,000 probability for a given year. The present-day model is the culmination of numerous laboratory experiments with an initial cross-shore profile based on the central Netherlands coast. Large parts of the dune coast of the Wadden islands have substantially different dune and cross-shore profile characteristics than found along this central coast, related to the presence of tidal channels, ebb-tidal deltas, beach-plains and strong coastal curvature. This complicated coastal setting implies that the predictions of the dune-erosion model are sometimes doubtful; accordingly, a shift towards a process-based dune-erosion model has been proposed. A number of research findings based on recent laboratory and field studies highlight only few of the many challenges that need to be faced in order to develop and test such a model. Observations of turbulence beneath breaking waves indicate the need to include breaking-wave effects in sand transport equations, while current knowledge of infragravity waves, one of the main sand transporting mechanisms during severe storm conditions, is strongly challenged by laboratory and field observations on gently sloping beaches that are so typical of the Wadden islands. We argue that in-situ and remote-sensing field observations, laboratory experiments and numerical models need to be the pillars of Earth Scientific research in the Wadden Sea area to construct a meaningful process-based dune-erosion tool.

Database of full-scale laboratory experiments on wave-driven sand transport processes

2009 ◽  
Vol 56 (7) ◽  
pp. 726-732 ◽  
Author(s):  
Jebbe J. van der Werf ◽  
Jolanthe J.L.M. Schretlen ◽  
Jan S. Ribberink ◽  
Tom O'Donoghue
Keyword(s):  
Laboratory Experiments ◽  
Transport Processes ◽  
Full Scale ◽  
Sand Transport

scholarly journals Estimating Annual Onshore Aeolian Sand Supply from the Intertidal Beach Using an Aggregated-Scale Transport Formula

2018 ◽  
Vol 6 (4) ◽  
pp. 127 ◽  
Author(s):  
Leonardo Duarte-Campos ◽  
Kathelijne Wijnberg ◽  
Suzanne Hulscher
Keyword(s):  
Moisture Content ◽  
High Tide ◽  
Sand Transport ◽  
Wind Gust ◽  
Aeolian Sand ◽  
Aeolian Transport ◽  
Aeolian Sand Transport ◽  
Sand Supply ◽  
Transport Prediction ◽  
High Tide Line

In this paper, we explore an approach for annual-scale transport prediction from the intertidal beach, in which we aggregate the surface conditions of the intertidal beach, in particular moisture content and roughness, and use hourly monitoring data of wind speed and wind direction. For our case study area (Egmond Beach, The Netherlands), we include Argus video imagery in our analysis to assess the occurrence of aeolian sand transport. With the approach described to determine a characteristic moisture content value for aeolian transport, we obtained surface moisture values of 1.2% to 3.2% for wind average and wind gust respectively, implying that we need a quite dry beach. This indicates that the main area for aeolian transport corresponds to the upper part of the intertidal source, most likely the region between mean high tide line and spring high tide line.

The effects of artificial pebble concentrations on eolion sand transport on a beach

1997 ◽  
Vol 34 (11) ◽  
pp. 1499-1508 ◽  
Author(s):  
Robin G. D. Davidson-Arnott ◽  
Davina C. White ◽  
Jeff Ollerhead
Keyword(s):  
Sediment Transport ◽  
Laboratory Experiments ◽  
Three Dimensional ◽  
Effective Area ◽  
Sand Transport ◽  
Data Sets ◽  
Ceramic Tiles ◽  
Sand Beach ◽  
Random Array ◽  
Protected Surface

A field experiment to measure the effects of differing concentrations of pebbles on rate of eoliao sediment transport was carried out on a sand beach on the Northumberland Strait, New Brunswick. Square ceramic tiles (0.15 m × 0.15 m) were used to replicate pebbles. These were deployed in a stratified random array in a rectangular plot 5 m wide and 2 m deep at five different concentrations (surface covers of 19, 24, 29, 34, and 44%) and both singly (two dimensional) and stacked three high (three dimensional). An adjacent plot of similar size was left bare and served as a control. Sediment transport was measured with pairs of vertical traps deployed downwind from each plot and wind speed with three-cup anemometers. Nine data sets totalling 45 runs of 10 min duration each were collected over a total of 4 days. Sediment transport over the tiled plot was normalized against transport over the bare plot. The results show an increase in sediment transport compared with the bare surface for the lowest coverage, followed by a continuous decrease in transport with increasing coverage up to the maximum coverage employed. The rate of decrease was greatest for runs that utilized a three-dimensional form, reflecting an increase in the effective area protected. The results confirm laboratory experiments, which suggest that erosion and transport are initially enhanced by acceleration of flow around pebbles and more efficient transport over the hard surface, but that this is counteracted at higher coverage densities by the increasing area of protected surface.

Covering of cometary nucleus by refractory crust and its evolution into asteroid-like body

1999 ◽  
Vol 173 ◽  
pp. 365-370
Author(s):  
Kh.I. Ibadinov
Keyword(s):  
Laboratory Experiments ◽  
Cometary Nucleus ◽  
Sublimation Rate ◽  
Cometary Nuclei ◽  
Short Period Comet ◽  
Short Period ◽  
Brightness Decrease ◽  
Crust Thickness ◽  
Ice Sublimation ◽  
Period Comet

AbstractFrom the established dependence of the brightness decrease of a short-period comet dependence on the perihelion distance of its orbit it follows that part of the surface of these cometary nuclei gradually covers by a refractory crust. The results of cometary nucleus simulation show that at constant insolation energy the crust thickness is proportional to the square root of the insolation time and the ice sublimation rate is inversely proportional to the crust thickness. From laboratory experiments resulted the thermal regime, the gas productivity of the nucleus, covering of the nucleus by the crust, and the tempo of evolution of a short-period comet into the asteroid-like body studied.

When Does Voice Have to be More Than Only Listening? Procedural Justice Effects as a Function of Confident Leadership

2010 ◽  
Vol 9 (2) ◽  
pp. 69-78 ◽  
Author(s):  
David De Cremer ◽  
Maarten Wubben
Keyword(s):  
Procedural Justice ◽  
Interaction Effect ◽  
Laboratory Experiments ◽  
Negative Emotions

The present research examined how voice procedures and leader confidence affect participants’ negative emotions and willingness to withdraw. It was predicted that receiving voice would be valued out of instrumental concerns, but only when the enacting leader was high in confidence. Two laboratory experiments indeed showed an interaction between type of voice (pre-decisional vs. post-decisional) and leader’s confidence (low vs. high) on participants’ negative emotions and willingness to withdraw. In particular, post-decision voice only led to more negative responses than did pre-decision voice when the enacting leader was high in confidence. Negative emotions mediated this interaction effect of type of voice on willingness to withdraw. Implications for integrating the leadership and procedural justice literatures are discussed.

Review of Laboratory Experiments in Psychology.

1968 ◽  
Vol 13 (10) ◽  
pp. 536-536
Author(s):  
Peter G. Polson
Keyword(s):  
Laboratory Experiments
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