Field Observation of the Wave-Induced Water Particle Velocity in the Surf Zone

1980 ◽  
Vol 23 (1) ◽  
pp. 81-89 ◽  
Author(s):  
Masaru Mizuguchi ◽  
Masahiko Isobe ◽  
Shintaro Hotta ◽  
Kiyoshi Horikawa
Keyword(s):  
Particle Velocity ◽  
Field Observation ◽  
Surf Zone ◽  
Water Particle ◽  
Wave Induced

Wave‐Induced Longshore Currents in Surf Zone

1994 ◽  
Vol 120 (6) ◽  
pp. 557-575 ◽  
Author(s):  
Donghoon Yoo
Keyword(s):  
Surf Zone ◽  
Longshore Currents ◽  
Wave Induced

scholarly journals DEVELOPMENT OF WAVE POWER GENERATION SYSTEM SUITABLE FOR INNER BAY

2020 ◽  
pp. 39
Author(s):  
Rioko Hirota ◽  
Takaaki Shigematsu ◽  
Kenji Katoh ◽  
Tatsuro Wakimoto ◽  
Shinya Yoshioka
Keyword(s):  
Power Generation ◽  
Particle Velocity ◽  
High Energy ◽  
Wave Power ◽  
Generation System ◽  
Water Particle ◽  
Water Turbine ◽  
Power Generation System ◽  
The Relationship ◽  
Wave Power Generation

With the increasing demand for renewable energy in the world, research contributing to the improvement of the technology level of wave power generation is essential. The authors have been developed a wave power generation system using port facilities in inner bays with high energy-consuming cities. In this study, the relationship between the rotational characteristics of a Savonius water turbine and the water particle velocity was quantitatively evaluated under the calm conditions of the inner bay, such as wave motion, flow, and coexistence of wave and current. According to the experimental results, it is found that the relationship between the rotational circumferential speed and the water particle velocity of the water turbine installed in a wave field tends to be different from that in a flow field and is evaluated by different equations. In addition, the relationship between circumferential velocity and the water particle velocity has also been formulated when installed in a wave-current coexistence field.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/KX0XBFuao48

scholarly journals KINEMATICS OF BREAKING WAVES

1976 ◽  
Vol 1 (15) ◽  
pp. 25 ◽  
Author(s):  
Edward B. Thornton ◽  
James J. Galvin ◽  
Frank L. Bub ◽  
David P. Richardson
Keyword(s):  
Solitary Waves ◽  
Particle Velocity ◽  
Asymptotic Expression ◽  
Breaking Waves ◽  
The Body ◽  
Time Dependent ◽  
Wave Crest ◽  
Periodic Waves ◽  
Water Particle ◽  
Highly Nonlinear

The sight and sound of breaking waves and surf is so familiar and enjoyable that we tend to forget how little we really understand about them. Why is it, that compared to other branches of wave studies our knowledge of breaking waves is so empirical and inexact? The reason must lie partly in the difficulty of finding a precise mathematical description of a fluid flow that is in general nonlinear and time-dependent. The fluid accelerations can no longer be assumed t o be small compared t o gravity, as in Stokes's theory for periodic waves and the theory of cnoidal waves in shallow water, nor is the particle velocity any longer small compared to the phase velocity. The aim of this paper is to bring together s ome recent contributions to the calculation both of steep symmetric waves and of time-dependent surface waves. These have a bearing on the behaviour of whitecaps in deep water and of surf in the breaker zone . Since spilling breakers in gently shoaling water closely resemble solitary waves, we begin with the description of solitary waves of limiting amplitude, then discuss steep waves of arbitrary height. The observed intermittency of whitecaps is discussed in terms of the energy maximum, as a function of wave steepness, In Sections 6 and 7 a simpler description of steady symmetric waves is proposed, using an asymptotic expression for the flow near the wave crest. Finally we describe a new numerical technique (MEL, or mixed Eulerian-Lagrangian) with which it has been found possible to follow the development of periodic waves past the point when overturning takes place. Measurement of waves, and vertical and horizontal water particle velocities were made of spilling, plunging and surging breakers at sandy beaches in the vicinity of Monterey, California. The measured breaking waves, derived characteristically from swell-type waves, can be described as highly nonlinear. Spectra and cross spectra were calculated between waves and velocities. Secondary waves were noted visually and by the strong harmonics in the spectra. The strength of the harmonics is related to the beach steepness, wave height and period. The phase difference between waves and horizontal velocities indicates the unstable crest of the wave leads the velocities on the average by 5-20 degrees. Phase measurements between wave gauges in a line perpendicular to the shore show breaking waves to be frequency nondispersive indicating phase-coupling of the various wave components. The coherence squared values between the sea surface elevation and the horizontal water particle velocity were high in all runs, ranging above 0.8 at the peak of the spectra. The high coherence suggests that most of the motion in the body of breaking waves is wave-induced and not turbulent.

scholarly journals Wave-Induced Sediment Motion Beyond the Surf Zone: Case Study of Lubiatowo (Poland)

2015 ◽  
Vol 62 (1-2) ◽  
pp. 27-39 ◽  
Author(s):  
Grzegorz R. Cerkowniak ◽  
Rafał Ostrowski ◽  
Magdalena Stella
Keyword(s):  
Surf Zone ◽  
Shear Stresses ◽  
Research Station ◽  
Wave Parameters ◽  
Sea Bottom ◽  
Theoretical Investigations ◽  
Deep Water Wave ◽  
Offshore Wave ◽  
Wave Induced

AbstractThe paper presents results of field and theoretical investigations of a natural sandy shore located near the IBW PAN Coastal Research Station in Lubiatowo (Poland, the south Baltic Sea). The study site displays multi-bar cross-shore profiles that intensively dissipate wave energy, mostly by breaking. The main field data comprise offshore wave parameters and three cross-shore bathymetric profiles. Waveinduced nearbed velocities and bed shear stresses are theoretically modelled for weak, moderate, strong and extreme storm conditions to determine sediment motion regimes at various locations on the seaward boundary of the surf zone. The paper contains a discussion on the depth of closure concept, according to which the offshore range of sea bottom changes can be determined by the extreme seasonal deep-water wave parameters.

scholarly journals The impact of wave energy converter arrays on wave-induced forcing in the surf zone

2018 ◽  
Vol 161 ◽  
pp. 322-336 ◽  
Author(s):  
Annika O'Dea ◽  
Merrick C. Haller ◽  
H. Tuba Özkan-Haller
Keyword(s):  
Wave Energy ◽  
Surf Zone ◽  
Wave Energy Converter ◽  
Energy Converter ◽  
Wave Induced ◽  
The Impact

scholarly journals VORTEX FORMATION IN PLUNGING BREAKER

1986 ◽  
Vol 1 (20) ◽  
pp. 54 ◽  
Author(s):  
T. Sakai ◽  
T. Mizutani ◽  
H. Tanaka ◽  
Y. Tada
Keyword(s):  
Flow Visualization ◽  
Particle Velocity ◽  
Vortex Formation ◽  
Water Particle ◽  
Mac Method ◽  
Long Wave ◽  
Wave Celerity ◽  
Maximum Water ◽  
Slope Beach ◽  
Plunging Breaker

By a flow visualization of a plunging breaker on 1/20 slope beach in a wave tank, an existence of 2nd and 3rd horizontal vortices(Miller, 1976) and slanting vortex (Nadaoka et al., 1986) is confirmed. A MAC method is applied to simulate a violent motion after an impinging of a jet from a crest of a plunging breaker on the trough surface. The calculated maximum water particle velocity in the jet is found to reach three times the linear long wave celerity. Values of circulation of the first four horizontal vortices are calculated and their changes in time are discussed.

scholarly journals Temperature gradient-type micro flowmeter for the measurement of water particle velocity of tidal wave.

1987 ◽  
pp. 135-143
Author(s):  
Fusetsu TAKAGI ◽  
Kiyoshi WADA ◽  
Shunroku NAKAMURA
Keyword(s):  
Temperature Gradient ◽  
Particle Velocity ◽  
Tidal Wave ◽  
Water Particle ◽  
Gradient Type

scholarly journals FIELD OBSERVATION ON SUSPENDED-LOAD IN THE SURF ZONE

1984 ◽  
Vol 1 (19) ◽  
pp. 124 ◽  
Author(s):  
Kazumasa Katoh ◽  
Norio Tanaka ◽  
Isao Irie
Keyword(s):  
Current Velocity ◽  
Field Observation ◽  
Surf Zone ◽  
Middle Layer ◽  
Suspended Load ◽  
The Other ◽  
Data Analyses ◽  
Other Hand ◽  
Incident Waves ◽  
Mean Concentration

Both the concentration of suspended-load and the current velocity have been measured continuously in the surf zone. In order to measure the concentration of the suspended-load in the surf zone, a optical densitometer has been developed. The current velocity was measured by means of electromagnetic current meters. According to data analyses, the mean concentration of the suspended-load is high in the final breaking zone and in the breaker zone. In the final breaking zone, the concentration fluctuates with the period of the incident waves. On the other hand, it fluctuates with the period longer than 40 seconds in the breaker zone and it becomes high when the current is offshoreward. The directions of the net transport of the suspendedload in the middle layer in and near the surf zone are offshoreward.

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