scholarly journals Features of vortical suppression of tsunami waves underwater barriers

2019 ◽  
Vol 484 (6) ◽  
pp. 755-759
Author(s):  
B. V. Boshenyatov ◽  
K. N. Zhiltsov
Keyword(s):  
Wave Height ◽  
Incident Wave ◽  
Wave Energy ◽  
Maximum Effect ◽  
Tsunami Waves ◽  
Incident Wave Energy

The features of vortical suppression of tsunami waves by an impermeable underwater barrier have been studied. The height of the barrier is close to the optimum corresponding to the maximum effect of vortical suppression of the wave energy. It is shown that the energy of suppressing tsunami waves by such a barrier depends on the wave height and can vary from zero to 80% of the incident wave energy.

scholarly journals Wave Breaker Model of Transmission Waves

2021 ◽  
Vol 2 (1) ◽  
pp. 35-40
Author(s):  
Phetthanan Sukaphone ◽  
Buonkun Ounlesy Yaxasiht
Keyword(s):  
Wave Height ◽  
Incident Wave ◽  
Wave Energy ◽  
Water Waves ◽  
Wave Reflection ◽  
Reflection Coefficients ◽  
The Waves ◽  
Incident Wave Energy

The wavelength, the wave height, and the depth of the water under which the waves travel are critical criteria for describing water waves. According to previous research, the depth and period of the waves have a significant effect on the propagation and reflection coefficients. The hollow breakwater's varied model is supposed to minimize wave reflection and propagation in addition to reducing wave reflection, due to its capacity to capture and reduce incident wave energy. 

Evaluation of Incident Wave Energy in Flume Tests

1987 ◽  
Author(s):  
Eliezer Kit ◽  
Oded Gottlieb ◽  
Dov S. Rosen
Keyword(s):  
Incident Wave ◽  
Wave Energy ◽  
Flume Tests ◽  
Incident Wave Energy

scholarly journals FIELD EXPERIMENT ON BEACH GRAVEL TRANSPORT

1978 ◽  
Vol 1 (16) ◽  
pp. 101 ◽  
Author(s):  
Masataro Hattori ◽  
Takasuke Suzuki
Keyword(s):  
Field Experiment ◽  
Incident Wave ◽  
Wave Energy ◽  
Transport Processes ◽  
Central Japan ◽  
Selective Transport ◽  
Longshore Transport ◽  
Wave Energy Flux ◽  
The Mean ◽  
Incident Wave Energy

To examine the longshore transport processes of beach gravels under wave action, a field experiment was performed by tracing the dacite blocks injected on Fuji Coast, Shizuoka Prefecture, Central Japan. The mean dislocating velocity of the tracer was 2 to 3 m/day under normal sea conditions, while under storm conditions it reached about 400 m/day. This -velocity was fairly proportional to the longshore component of incident wave energy flux. The longshore variations of the size and shape of beach gravels were mainly resulted from the progressive attrition and impact breakage of beach gravels rather than from the selective transport.

Do longshore bars shelter the shore?

2000 ◽  
Vol 404 ◽  
pp. 251-268 ◽  
Author(s):  
JIE YU ◽  
CHIANG C. MEI
Keyword(s):  
Spatial Distribution ◽  
Incident Wave ◽  
Wave Energy ◽  
Phase Relation ◽  
Bragg Reflection ◽  
Qualitative Change ◽  
Numerical Calculations ◽  
Reflected Waves ◽  
Incident Waves ◽  
Incident Wave Energy

In most past theories on Bragg reflection of waves by a finite patch of rigid bars, only outgoing waves are allowed on the transmission side, simulating the effect of an idealized shoreline where all the incident wave energy is consumed by breaking. In these theories the amplitudes of both the incident and reflected waves are found to decrease monotonically over the bar patch in the shoreward direction. This result has motivated the idea of artificially constructing bars to protect a beach from incident waves. However, some numerical calculations have suggested that this tendency does not always hold when there is some reflection from the shore. We show here that with finite reflection by the shoreline the spatial distribution of wave energy over the patch can indeed be reversed, indicating that the mechanism can increase the hazards to the beach. The phase relation between the bars and the shoreline reflection is found to be the key to this qualitative change of wave response.

scholarly journals RESEARCHES ON SEA-WALLS

1970 ◽  
Vol 1 (12) ◽  
pp. 88
Author(s):  
S. Nagal
Keyword(s):  
Incident Wave ◽  
Wave Energy ◽  
Precast Concrete ◽  
Recent Decade ◽  
Point Of View ◽  
Industrial Firms ◽  
Wave Overtopping ◽  
Port Facilities ◽  
Sea Wall ◽  
Incident Wave Energy

In the recent decade, very wide areas of sea where the depths of water are from several meters to ten meters or more during storms have been reclaimed for industrial firms and port facilities in many places in Japan As the incident wave energy in such cases is very large at the sea-walls, the protection of the reclaimed lands from wave overtopping by the conventional sea-walls of vertical type or composite-slope«and-berai type is generally impossible from an economical point of view In Japan a special type of sea-wall, which is of such a type that a rubble-mound covered with specially shaped precast concrete armor blocks is built in front of the sea-wall to absorb most of the incident wave energy, has been constructed to protect the reclaimed lands from wave overtopping Most of the seawalls have been proved satisfactory after passing of typhoons over or near the sea-walls The design of the sea-walls is presented here in by showing the comparisons between the experiments and prototypes during typhoons.

Model Experiment on an OWC-Type Wave-Energy Converter With Hydraulic Power Take-Off

2002 ◽  
Author(s):  
Torkel Bjarte-Larsson ◽  
Per Magne Lillebekken ◽  
Jo̸rgen Hals ◽  
Johannes Falnes
Keyword(s):  
Incident Wave ◽  
Wave Energy ◽  
Wave Energy Converter ◽  
Laboratory Model ◽  
Energy Converter ◽  
Hydraulic Power ◽  
Optimum Load ◽  
Wave Channel ◽  
Period 2 ◽  
Incident Wave Energy

A wave-energy converter of the OWC type is described, in which the absorbed wave energy is converted to useful energy by means of a hydraulic power take-off. Means are provided to enable the float to be latched for phase control. The float is connected to a piston pump, which pumps water from the level of the water in the wave channel to a higher level, which is adjustable. By means of measurements from three wave gauges (two on the upstream side and one on the downstream side) the incident wave energy and the absorbed wave energy are derived. For a down-scaled laboratory model, resonance is obtained with an incident sinusoidal wave of period 1 s. With optimum load, the converted useful hydraulic energy is a fraction of 0.2 of the incident wave energy. The absorbed wave energy is then 0.6 units of the incident wave energy. With wave period 2 s and optimum load, these energy fractions are 0.03 and 0.13, which are increased to 0.05 and 0.21, respectively, when latching control is applied.

Regularly-spaced grooves on shore platforms in north Northumberland, UK

2020 ◽  
Vol 63 (2) ◽  
pp. 124-134
Author(s):  
Alison M. Tymon ◽  
Barry G. Tymon
Keyword(s):  
Incident Wave ◽  
Wave Energy ◽  
Surf Zone ◽  
High Water ◽  
Edge Waves ◽  
Shore Platform ◽  
Bedding Planes ◽  
High Water Mark ◽  
Incident Wave Energy ◽  
Shore Platforms

Unusual regularly-spaced grooves are found between low water mark (LWM) and high water mark (HWM) on several shore platforms in north Northumberland. References in the literature are sparse, so data were collected to establish the nature of the grooves and to elucidate the processes that might have formed them. Groove formation is confined to strata with widely spaced bedding planes on shore platforms dipping at no more than 5° towards the sea. The grooves are symmetrical, bifurcation is common and grooves on sandstones are deeper and more sinuous than those on limestones. Grooves at mid-tide levels are wider than grooves near LWM and HWM and the trend of the grooves is not related to joint trends. The process that has formed the characteristically smooth surfaces of the grooves is considered to be abrasion by sand and pebbles carried by waves in the surf zone of the shore platform. The width of the grooves is remarkably regular, and it is suggested that this may be due to the effects of the increase in incident wave energy given by edge waves.

scholarly journals EVALUATION OF INCIDENT WAVE ENERGY IN FLUME TEST

1986 ◽  
Vol 1 (20) ◽  
pp. 93
Author(s):  
Eliezer Kit ◽  
Oded Gottlieb ◽  
Dov S. Rosen
Keyword(s):  
Least Squares ◽  
Incident Wave ◽  
Wave Energy ◽  
Least Squares Method ◽  
Stationary Wave ◽  
Residual Energy ◽  
Irregular Waves ◽  
Wave Spectra ◽  
Reflected Wave ◽  
Incident Wave Energy

A two dimensional model study, carried out for a structure in a flume using irregular waves, presents the problem of determining the relationship between the total incident wave energy attacking the structure and its response to that attack (displacements, forces, etc.) in various sea states, The total incident wave energy can be evaluated indirectly only, because the wave energy measured in the flume contains an extent of residual wave energy in addition to that generated by the wave machine. This residual energy consists of the re-reflected wave energy from the paddle of the wave machine, assuming the existence of quasi-stationary wave conditions in the flume. A method originally presented by Gravesen et al. (1974), was applied in this study to evaluate the total incident wave energy. In view of the results obtained by this method, a physically more sound refinement is proposed for the evaluation of the total incident wave energy (and characteristic wave height). Results of model tests were analyzed by the CAMERI refinement and compared with the Gravesen method and with a cross-spectral least squares method, separating incident and reflected wave spectra from wave spectra measured in the flume, Good agreement was found between the results obtained employing the CAMERI refinement and the cross-spectral least squares method, Advantages and drawbacks of these methods are indicated,

Numerical Analysis of the Oscillating Water Column (OWC) Wave Energy Converter (WEC) Considering Different Incident Wave Height

2017 ◽  
Vol 370 ◽  
pp. 120-129
Author(s):  
Mateus das Neves Gomes ◽  
Eduardo Alves Amado ◽  
Elizaldo Domingues dos Santos ◽  
Liércio André Isoldi ◽  
Luiz Alberto Oliveira Rocha
Keyword(s):  
Water Column ◽  
Wave Height ◽  
Incident Wave ◽  
Wave Energy ◽  
Amplification Factor ◽  
Wave Energy Converter ◽  
Geometric Shape ◽  
Oscillating Water Column ◽  
Energy Converter ◽  
Incident Waves

The ocean wave energy conversion into electricity has been increasingly researched in the last years. There are several proposed converters, among them the Oscillating Water Column (OWC) device has been widely studied. The present paper presents a two-dimensional numerical investigation about the fluid dynamics behavior of an OWC Wave Energy Converter (WEC) into electrical energy. The main goal of this work was to numerically analyze the optimized geometric shape obtained in previous work under incident waves with different heights. To do so, the OWC geometric shape was kept constant while the incident wave height was varied. For the numerical solution it was used the Computational Fluid Dynamic (CFD) commercial code FLUENT®, based on the Finite Volume Method (FVM). The multiphasic Volume of Fluid (VOF) model was applied to tackle with the water-air interaction. The computational domain is represented by the OWC device coupled with the wave tank. This work allowed to check the influence of the incident wave height on the hydropneumatic power and the amplification factor of the OWC converter. It was possible to identify that the amplification factor increases as the wave period increases, thereby improving the OWC performance. It is worth to highlight that in the real phenomenon the incident waves on the OWC device have periods, lengths and height variables.

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