scholarly journals WAVE ENERGY DISSIPATION IK ROCKFILL

1972 ◽  
Vol 1 (13) ◽  
pp. 103
Author(s):  
John A. McCorquodale
Keyword(s):  
Wave Energy ◽  
Granular Media ◽  
Present Report ◽  
Internal Flow ◽  
Wave Action ◽  
Darcy Flow ◽  
Water Level Fluctuations ◽  
Wave Energy Dissipation ◽  
The Stability ◽  
External Wave

Very little literature exists on the subject of unsteady non-Darcy flow in coarse granular media. However, unsteady non-Darcy flow is encountered in a few important hydraulic problems, for example, (a) Wave absorption and transmission in rubble-mound break-waters; (b) Water level fluctuations in the rockfill and filter zones of a dam subjected to wave action; (c) Transmission of floods or tides through rockfill dams and causeways, A mathematical model, to simulate the internal Darcy and/or non-Darcy flow in an embankment subjected to wave action, would permit an improved analysis of: the stability of the embankment; the stability of the armour layer; and the absorption and dissipation of wave energy by the rockfill. Since the internal flow in the embankment and the external wave action are interdependent, a complete model requires the simulation of both of these flows. Such a model would permit the computation of wave run-up and reflection. The present report is limited to the simulation of the unsteady internal flow. Heitner and Housner (4), using a finite element method, have developed an external wave action simulation for Tsunamis. The author is presently attempting to couple the internal and external models.

scholarly journals EXPERIMENTAL RESEARCH IN FORMATION BY WAVES OF STABLE PROFILES OF UPSTREAM FACES OF EARTH DAMS AND RESERVOIR SHORES

2011 ◽  
Vol 1 (7) ◽  
pp. 16
Author(s):  
I.J. Popov
Keyword(s):  
Wave Energy ◽  
Wave Action ◽  
Shore Protection ◽  
Earth Dams ◽  
Wave Energy Dissipation ◽  
Stage Of Development ◽  
Initial Stage ◽  
Protective Cover ◽  
Engineering Measure ◽  
Underwater Slope

Within the last few years the Soviet hydraulic engineers have been making continuous efforts to avoid use of concrete slabs and blocks and stone riprap as protective cover of upstream slopes of earth dams and reservoir shores against the disrupting effects of waves generated by the action of wind upon the water surface. Their efforts have been aimed at finding the cheaper procedure. Of all the possible ways of slope and shore protection, an engineering measure, the idea of which consists in distributing the wave energy dissipation over a considerably large portion of a sufficiently gentle slope, should be given a special attention. This measure makes it possible to substantially relieve the protective cover and in some cases to leave the slope uncovered. The possibility of unlined slopes, stable enough agains wave action is proved out by the experience of reservoir operation. Shores and underwater slopes of artificial lakes composed of non-cohesive soils are usually subject to considerable disintegration due to wave action. The process of disintegration which goes on rather fast at the initial stage of lake existence, slowff down with the formation of a flat lake-side shallow, whereon dissipation of wave energy takes place. At a certain stage of development the underwater slope assumes such dimensions and outlines which enable it to dissipate the whole of the wave energy and practically to protect shores from further destruction. The profile of the slope at which it will permanently stand underwater is referred to as the "profile of equilibrium" or "dynamically stable profile". The term "equilibrium" in this case doesn't imply absolute immovability of the material acted on by waves, but stands for such a movable state at which particles of the soil are making oscillatory movements round some middle position without the resultant movement neither towards nor off shore.

Numerical and Experimental Analysis of a Hybrid Wind-Wave Offshore Floating Platform’s Hull

2018 ◽  
Author(s):  
Thiago S. Hallak ◽  
José F. Gaspar ◽  
Mojtaba Kamarlouei ◽  
Miguel Calvário ◽  
Mário J. G. C. Mendes ◽  
...  
Keyword(s):  
Wave Energy ◽  
Experimental Analysis ◽  
Wind Wave ◽  
Numerical Study ◽  
Energy Devices ◽  
Wave Energy Converters ◽  
Wave Basin ◽  
Hybrid Concept ◽  
Point Absorbers ◽  
The Stability

This paper presents a study regarding a novel hybrid concept for both wind and wave energy offshore. The concept resembles a semi-submersible wind platform with a larger number of columns. Wave Energy Devices such as point absorbers are to be displayed around the unit, capturing wave energy while heaving and also enhancing the stability of the platform. In this paper, a first numerical study of the platform’s hull, without Wave Energy Converters, is carried out. Experiments in wave basin regarding the same unit have been conducted and the results are presented and compared to the numerical ones. Both stability and seakeeping performances are assessed and compared.

scholarly journals ARPEC: A NOVEL STAGGERED PERFORATED CAISSON FOR WAVE ABSORPTION AND TIDAL FLUSHING

2020 ◽  
pp. 26
Author(s):  
Paolo Sammarco ◽  
Leopoldo Franco ◽  
Giorgio Bellotti ◽  
Claudia Cecioni ◽  
Stefano DeFinis
Keyword(s):  
Energy Dissipation ◽  
Water Flow ◽  
Wave Energy ◽  
Reflection And Transmission ◽  
Wave Energy Dissipation ◽  
Wave Absorption ◽  
Transmission Coefficients ◽  
Open Sea ◽  
Caisson Breakwater ◽  
Perforated Caisson

An innovative caisson breakwater geometry (patent pending) named "ARPEC" (Anti Reflective PErmeable Caisson) includes openings at all external and internal walls and at lateral (cross) ones, yet in a staggered pattern, to provide a labyrinthian hydraulic communication between the open sea and the internal waters. The complex sinuous water-flow within the consecutive permeable chambers thus favors wave energy dissipation as well as port water flushing and quality, with very low reflection and transmission coefficients. 2D lab model tests demonstrate the system effectiveness.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/PaUsinYO-Zo

The role of solution chemistry in the stability and detachment of cohesive kaolinite particles

2001 ◽  
Vol 1 (1) ◽  
pp. 25-32 ◽  
Author(s):  
V. Ravisangar ◽  
B.M. Brouckaert ◽  
A. Amirtharajah ◽  
T.W. Sturm
Keyword(s):  
Granular Media ◽  
Interaction Force ◽  
Solution Chemistry ◽  
Force Model ◽  
Concentrated Suspensions ◽  
Sediment Deposits ◽  
The Stability ◽  
Relationship Of ◽  
Filter Backwashing

The effect of solution chemistry on the behavior of kaolinite in three different situations was investigated: (1) the detachment of kaolinite from glass beads in a fluidized bed, (2) the erosion of kaolinite deposits in a laboratory flume and (3) the determination of the stress-strain rate relationship of concentrated suspensions in a rheometer. The experimental results from these three different approaches could be explained in terms of changes in mode of particle associations which in turn could be characterized in terms of a micromechanical force model which predicts the effect of solution chemistry on the interaction force between adjacent particle surfaces. Understanding the relationship between solution and surface chemistry on the structure, mechanical strength and mechanism of erosion of cohesive sediment deposits is an important step towards developing predictive models of a number of processes including erosion of cohesive sediments in streams and estuaries, and detachment of particles from granular media during filtration and filter backwashing.

scholarly journals A Design for Vortex Suppression Downstream of a Submerged Gate

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 750
Author(s):  
Ender Demirel ◽  
Mustafa M. Aral
Keyword(s):  
Internal Flow ◽  
Vortex Pair ◽  
Horseshoe Vortex ◽  
Vortex Structures ◽  
Downstream Face ◽  
Mean Flow ◽  
Mean Velocity ◽  
Eddy Simulation ◽  
Drag Forces ◽  
The Stability

Interaction of recirculating and mean flow downstream of a submerged gate may form significant vortex structures, which may affect the stability of the gate. Although these flow structures that appear in submerged hydraulic jumps received considerable attention in the literature, relatively less work was devoted to the analysis and suppression of the vortex structures downstream of a submerged gate. In this work, internal flow structure and vortex dynamics around a submerged gate were investigated through laboratory tests and large-eddy simulation (LES) using computational fluid dynamics (CFD). It is shown that numerical results obtained for mean velocity field are in good agreement with the experimental measurements. A helical vortex pair connected with a horseshoe vortex system was identified within the roller region using high-resolution numerical simulations. Damping performance of different types of anti-vortex elements placed on the downstream face of the gate are evaluated based on numerical studies. It is shown that the horizontal porous baffle mounted at an elevation below the free surface reduced the vortex magnitudes in the roller region by 26.8%. With the implementation of the proposed vortex breaker, lift forces acting on the gate lip were reduced by 9.4% and drag forces acting on the downstream face of the gate were reduced by 8.6%. Finally, in this study, we assess the performance of the vortex breaker under different flow conditions.

Spectral wave flow attenuation within submerged canopies: Implications for wave energy dissipation

2007 ◽  
Vol 112 (C5) ◽  
Author(s):  
Ryan J. Lowe ◽  
James L. Falter ◽  
Jeffrey R. Koseff ◽  
Stephen G. Monismith ◽  
Marlin J. Atkinson
Keyword(s):  
Energy Dissipation ◽  
Wave Energy ◽  
Wave Flow ◽  
Wave Energy Dissipation ◽  
Flow Attenuation
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