WIND EFFECTS ON OVERTOPPING DISCHARGE AT COASTAL DEFENCES

Coastal Engineering Proceedings ◽

10.9753/icce.v36v.papers.40 ◽

2020 ◽

pp. 40

Author(s):

S De Chowdhury ◽

J. G. Zhou ◽

L. Qian ◽

D. Causon ◽

C. Mingham ◽

...

Keyword(s):

Wind Speed ◽

Shallow Water ◽

Physical Model ◽

Standing Waves ◽

Wave Interaction ◽

Wind Effects ◽

Wave Overtopping ◽

Defence System ◽

Type Wave

Wind effects on wave overtopping over fully impermeable vertical sea defence is studied in a shallow water flume based on a physical model for the Livermeade defence system. The investigation is mainly focused on impulse type wave interaction with the sea defence, when the overshooting jet is high during overtopping. We are able to identify distinct types of overtopping flows where moderate wind speed is not found to be affecting uniformly in all cases. We try to find explanation of this behaviours by studying the standing waves at the defence and complementary CFD simulations.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/byRz_N9zoXk

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ON THE EFFECT OF CURRENT ON WAVE RUN-UP AND WAVE OVERTOPPING

Coastal Engineering Proceedings ◽

10.9753/icce.v32.structures.13 ◽

2011 ◽

Vol 1 (32) ◽

pp. 13 ◽

Cited By ~ 2

Author(s):

Stefanie Lorke ◽

Anja Brüning ◽

Jentsje Van der Meer ◽

Holger Schüttrumpf ◽

Antje Bornschein ◽

...

Keyword(s):

Shallow Water ◽

Physical Model ◽

Short Description ◽

Test Results ◽

Wave Overtopping ◽

Oblique Wave ◽

Physical Model Tests ◽

Model Setup ◽

Run Up ◽

Sea Dikes

Intention of the project FlowDike-D is to quantify the impacts of current and wind on wave run-up and wave overtopping and to consider these processes in existing design formulae for estuarine, river and sea dikes. Physical model tests were carried out in the shallow water basin at DHI (Hørsholm/Denmark) for two different dike geometries (1:3 and 1:6 sloped dike). The paper introduces the model setup and test programme followed by a short description of the applied instrumentation. The test results for wave run-up and wave overtopping with oblique and non-oblique wave attack, but without current, correspond well with existing formulae from the EurOtop-Manual (2007). The influence of current parallel to the dike combined with different angles of wave attack on wave overtopping and wave run-up has been quantified. A distinction was made between wave attack with and against the current.

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Generation of Large Directional Wind Speed Data Sets for Estimation of Wind Effects with Long Return Periods

Journal of Structural Engineering ◽

10.1061/(asce)st.1943-541x.0000995 ◽

2014 ◽

Vol 140 (10) ◽

pp. 04014073 ◽

Cited By ~ 10

Author(s):

DongHun Yeo

Keyword(s):

Wind Speed ◽

Data Sets ◽

Return Periods ◽

Wind Effects ◽

Wind Speed Data

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Wind effects in shallow‐water acoustic transmission

The Journal of the Acoustical Society of America ◽

10.1121/1.398713 ◽

1989 ◽

Vol 86 (4) ◽

pp. 1530-1545 ◽

Cited By ~ 19

Author(s):

David E. Weston ◽

Pamela A. Ching

Keyword(s):

Shallow Water ◽

Wind Effects ◽

Acoustic Transmission

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Comment on “Grazing incidence X-ray fluorescence of periodic structures – a comparison between X-ray standing waves and geometrical optics calculations” by F. Reinhardt, S. H. Nowak, B. Beckhoff, J-C. Dousse and M. Schoengen, JAAS, 2014, 29, 1778

Journal of Analytical Atomic Spectrometry ◽

10.1039/c5ja00040h ◽

2015 ◽

Vol 30 (12) ◽

pp. 2548-2550

Author(s):

W. Jark ◽

D. Eichert

Keyword(s):

Physical Model ◽

Periodic Structures ◽

Standing Waves ◽

Grazing Incidence ◽

Data Interpretation ◽

Geometrical Optics ◽

X Ray ◽

Model Based ◽

Published Paper

The data interpretation in the recently published paper with the above title is criticized and it is shown that an alternative more physical model based on diffraction in periodic structures can explain the data better and more consistently.

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Validation of Wave Propagation in Numerical Wave Tanks

24th International Conference on Offshore Mechanics and Arctic Engineering: Volume 3 ◽

10.1115/omae2005-67221 ◽

2005 ◽

Cited By ~ 1

Author(s):

Tim Bunnik ◽

Rene´ Huijsmans

Keyword(s):

Shallow Water ◽

Model Test ◽

Water Depth ◽

Linear Potential ◽

Intermediate Water ◽

Numerical Wave Tank ◽

Wave Tank ◽

Type Wave ◽

Wave Generator ◽

Numerical Wave

During the last few years there has been a strong growth in the availability and capabilities of numerical wave tanks. In order to assess the accuracy of such methods, a validation study was carried out. The study focuses on two types of numerical wave tanks: 1. A numerical wave tank based a non-linear potential flow algorithm. 2. A numerical wave tank based on a Volume of Fluid algorithm. The first algorithm uses a structured grid with triangular elements and a surface tracking technique. The second algorithm uses a structured, Cartesian grid and a surface capturing technique. Validation material is available by means of waves measured at multiple locations in two different model test basins. The first method is capable of generating waves up to the break limit. Wave absorption is therefore modeled by means of a numerical beach and not by mean of the parabolic beach that is used in the model basin. The second method is capable of modeling wave breaking. Therefore, the parabolic beach in the model test basin can be modeled and has also been included. Energy dissipation therefore takes place according to physics which are more related to the situation in the model test basin. Three types of waves are generated in the model test basin and in the numerical wave tanks. All these waves are generated on basin scale. The following waves are considered: 1. A scaled 100-year North-Sea wave (Hs = 0.24 meters, Tp = 2.0 seconds) in deep water (5 meters). 2. A scaled operational wave (Hs = 0.086 meters, Tp = 1.69 seconds) at intermediate water depth (0.86 meters) generated by a flap-type wave generator. 3. A scaled operational wave (Hs = 0.046 meters, Tp = 1.2 seconds) in shallow water (0.35 meters) generated by a piston-type wave generator. The waves are generated by means of a flap or piston-type wave generator. The motions of the wave generator in the simulations (either rotational or translational) are identical to the motions in the model test basin. Furthermore, in the simulations with intermediate water depth, the non-flat contour of the basin bottom (ramp) is accurately modeled. A comparison is made between the measured and computed wave elevation at several locations in the basin. The comparison focuses on: 1. Reflection characteristics of the model test basin and the numerical wave tanks. 2. The accuracy in the prediction of steep waves. 3. Second order effects like set-down in intermediate and shallow water depth. Furthermore, a convergence study is presented to check the grid independence of the wave tank predictions.

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Study on the Efficiency and Dynamic Characteristics of an Energy Harvester Based on Flexible Structure Galloping

Energies ◽

10.3390/en14206548 ◽

2021 ◽

Vol 14 (20) ◽

pp. 6548

Author(s):

Peng Liao ◽

Jiyang Fu ◽

Wenyong Ma ◽

Yuan Cai ◽

Yuncheng He

Keyword(s):

Numerical Simulation ◽

Wind Speed ◽

Physical Model ◽

Energy Harvester ◽

High Efficiency ◽

Lateral Displacement ◽

Maximum Output Power ◽

Flexible Structure ◽

Maximum Output ◽

Cfd Numerical Simulation

According to the engineering phenomenon of the galloping of ice-coated transmission lines at certain wind speeds, this paper proposes a novel type of energy harvester based on the galloping of a flexible structure. It uses the tension generated by the galloping structure to cause periodic strain on the piezoelectric cantilever beam, which is highly efficient for converting wind energy into electricity. On this basis, a physical model of fluid–structure interaction is established, and the Reynolds-averaged Navier–Stokes equation and SST K -ω turbulent model based on ANSYS Fluent are used to carry out a two-dimensional steady computational fluid dynamics (CFD) numerical simulation. First, the CFD technology under different grid densities and time steps is verified. CFD numerical simulation technology is used to simulate the physical model of the energy harvester, and the effect of wind speed on the lateral displacement and aerodynamic force of the flexible structure is analyzed. In addition, this paper also carries out a parameterized study on the influence of the harvester’s behavior, through the wind tunnel test, focusing on the voltage and electric power output efficiency. The harvester has a maximum output power of 119.7 μW/mm3 at the optimal resistance value of 200 KΩ at a wind speed of 10 m/s. The research results provide certain guidance for the design of a high-efficiency harvester with a square aerodynamic shape and a flexible bluff body.

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IRREGULAR WAVE OVERTOPPING RATES

Coastal Engineering Proceedings ◽

10.9753/icce.v19.22 ◽

1984 ◽

Vol 1 (19) ◽

pp. 22 ◽

Cited By ~ 2

Author(s):

Scott L. Douglass

Keyword(s):

Shallow Water ◽

Shore Protection ◽

Coastal Structures ◽

Wave Overtopping ◽

Manual Method ◽

Irregular Wave ◽

Order Of Magnitude

Methods for estimating wave overtopping of coastal structures are reviewed and compared with the very limited available data and with each other. The different methods yield results which can vary more than an order-of-magnitude. For vertical seawalls, the U. S. Army Engineer Shore Protection Manual method estimates more overtopping than Goda's method except in very shallow water. For sloped structures, the Shore Protection Manual method usually estimates less overtopping than Battjes' method and Owen's method. However, data for adequately evaluating how well these methods predict overtopping has not been published.

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LARGE AND SMALL SCALE WAVE OVERTOPPING MEASUREMENTS FOR AFSLUITDIJK REHABILITATION PROJECT

Coastal Engineering Proceedings ◽

10.9753/icce.v36v.structures.15 ◽

2020 ◽

pp. 15

Author(s):

Wouter Ockeloen ◽

Coen Kuiper ◽

Sjoerd van den Steen

Keyword(s):

Water Management ◽

Physical Model ◽

Large Scale ◽

Wadden Sea ◽

Model Tests ◽

Small Scale ◽

Water Safety ◽

Wave Overtopping ◽

Physical Model Tests ◽

Large Scale Tests

The 'Afsluitdijk' is a 32 km enclosure dam which separates the Wadden sea and the Lake IJssel. The dam currently undergoes a major rehabilitation to meet the requirements with regard to water safety. The Dutch Ministry of infrastructure and Water Management (Rijkswaterstaat division) has commissioned Levvel, a consortium of BAM, Van Oord and Rebel, to prepare the design and carry out the reconstruction of the dam including sluices and highway. The project includes reinforcement of the armour layers and wave overtopping reduction. As part of the contract Rijkswaterstaat prescribed the contractor (Levvel) to verify the design with large scale physical model tests (min. 1:3 scale). These tests were carried out in the Delta Flume of Deltares. Prior to the large scale tests, smaller scale tests (1:20) have been carried out to optimize the design with regard to armour stability and wave overtopping. The research described here focuses on the wave overtopping.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/kPga0wVCCIE

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PHYSICAL MODEL TESTS ON WAVE OVERTOPPING AND FLOW PROCESSES ON DIKE CRESTS INFLUENCED BY WAVE-CURRENT INTERACTION

Coastal Engineering Proceedings ◽

10.9753/icce.v33.waves.34 ◽

2012 ◽

Vol 1 (33) ◽

pp. 34 ◽

Cited By ~ 2

Author(s):

Stefanie Lorke ◽

Babette Scheres ◽

Holger Schüttrumpf ◽

Antje Bornschein ◽

Reinhard Pohl

Keyword(s):

Physical Model ◽

Model Tests ◽

Longshore Current ◽

Wind Fields ◽

Incoming Wave ◽

Wave Overtopping ◽

Improve Design ◽

Physical Model Tests ◽

Flow Processes ◽

Run Up

Flow processes like flow depths and flow velocities give important information about erosion and infiltration processes, which can lead to an unstable dike structure and consequently to dike failure. Up to now several physical model tests on wave run-up and wave overtopping are available to adjust and improve design formula for different dike structures. This kind of physical model tests have been performed in the here presented project FlowDike. Its main purpose is to consider two new aspects that could influence the assessment of wave run-up and wave overtopping as well as the flow processes on dikes which have not been investigated yet: longshore current and wind. Especially in estuaries and along coasts, the effect of tidal and storm induced currents combined with local wind fields can influence the incoming wave parameters at the dike toe as well as the wave run-up height, the wave overtopping rate and the flow processes on dikes. This paper will focus on these flow processes on dike slopes and dike crests on an 1:6 sloped dike influenced by oblique wave attack and longshore current.

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