scholarly journals Interactions of Solitary Wave with a Submerged Step: Experiments and Simulations

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1302
Author(s):  
Wei-Ting Chao ◽  
Shin-Jye Liang ◽  
Chih-Chieh Young ◽  
Chao-Lung Ting
Keyword(s):  
Experimental Data ◽  
Solitary Wave ◽  
Wave Height ◽  
Step Height ◽  
Coastal Protection ◽  
Width Ratio ◽  
Step Width ◽  
Height Ratio ◽  
Hydrostatic Model ◽  
Series Of Experiments

A series of experiments exploring the propagation of a solitary wave over a submerged step were performed using a flow-field visualization measurement system, an image-connection technique as well as model simulations. The experimental data were used to validate a one-layer finite-element non-hydrostatic model and a multi-layer finite-difference non-hydrostatic σ model for various submerged step configurations and wave conditions—combinations of step height ratios d/h, width ratios B/h and solitary wave height ratios H/h, where d denotes the step height, B the step width, H the solitary wave height, and h the still water depth. The main differences between the numerical results and the experimental data are highlighted. The effect of the height and width of the submerged step as well as the wave height of the solitary wave are quantified in terms of reflection (R), transmission (T), and energy dissipation (D). Through a series of numerical experiments, an optimal combination of the height ratio d/h, width ratio B/h, and solitary wave height ratio H/h for breakwater design for coastal protection is suggested.

Solitary Wave Interaction With Vertical Porous Barriers

2019 ◽  
Author(s):  
Vivek Francis ◽  
Balaji Ramakrishnan ◽  
Murray Rudman
Keyword(s):  
Experimental Data ◽  
Energy Dissipation ◽  
Solitary Wave ◽  
Coastal Protection ◽  
Ocean Engineering ◽  
Tsunami Waves ◽  
Porous Barrier ◽  
Porous Barriers ◽  
Run Up ◽  
Protection Structures

Abstract Tsunami waves pose a threat to the coastal zone and numerous studies have been carried out in the past to understand them. The present study — carried out in the 2D wave flume at the Ocean Engineering Laboratory of IIT Bombay — focusses on the interaction and run-up of solitary waves on coastal protection structures in the form of thin, rigid vertical porous barriers with special attention given to the degree of energy dissipation. In order to understand the physics of the energy dissipation problem, the propagation of the solitary wave and its interaction with the porous barrier has been studied from the viewpoint of energy balance. Based on this, a proper relationship for the wave energy dissipated by the barrier has been developed. Using this relationship, the experimental data has been analyzed and we have determined that the plate porosity that gives the optimal energy dissipation characteristics lies within the 10–20% range. In addition, using the experimental data, we have derived a formula for calculating the maximum wave run-up on the porous barrier models which should be useful in the planning, design, construction and maintenance of coastal protection structures.

Motion Characteristics of Composite-Type Sea Cage under Pure Wave

2012 ◽  
Vol 490-495 ◽  
pp. 3405-3409
Author(s):  
Chun Liu Li ◽  
Yun Peng Zhao
Keyword(s):  
Experimental Data ◽  
Wave Height ◽  
Vertical Motion ◽  
Data Acquisition System ◽  
Horizontal Motion ◽  
Wave Condition ◽  
Composite Type ◽  
Motion Range ◽  
Motion Characteristics ◽  
Sea Cage

To study motion range changes with wave condition and motion relationship between cages, physical model experiments were carried out. The authors designed 2 models of composite-type sea cages. Experimental data obtained by the CCD data acquisition system. The experiment results showed that 1.in the same period, horizontal motion range,vertical motion range and inclination changes of float collar increase with wave height; 2.In the same wave height, horizontal motion range of the float collar increases with period; 3.The laws between vertical motion and period are not obvious 4.The laws between inclination changes and period are not obvious 5.Motion range of the first cage along the direction of waves is less than other cages.

Modeling of wave processes in closed water areas of shallow water areas

2021 ◽  
pp. 30-35
Author(s):  
Eugene Istomin ◽  
Valerii Mikheev ◽  
Yaroslav Petrov ◽  
Irma Martyn
Keyword(s):  
Water Area ◽  
Navier Stokes ◽  
Coastal Protection ◽  
Wave Processes ◽  
Color Palette ◽  
Continuity Equations ◽  
Port Area ◽  
Wave Heights ◽  
Closed Water ◽  
Hydrostatic Model

The article presents the developed non-stationary two-dimensional hydrostatic model of wave propagation in the water area of the port of the Bay of Five Hunters, protected by a coastal protection structure in the form of a jetty. The tasks of the work included the development of a model based on the Navier-Stokes and continuity equations and a long-range assessment of the possible impact of the wave situation on marine objects in the port area. At present, the provision of hydrometeorological predictive information is one of the most important factors in the effective operation of port waters. The results are presented graphically using a geographic information system, where different wave heights and maximum wave amplitudes are displayed using a color palette. The consistency of the obtained results is shown, and refraction, diffraction, and interference are noted for the incoming wavefront.

Experimental Design of Surface Modification of Expanded Obsidian and Determination of Water Sorption Capacity

2014 ◽  
Vol 1020 ◽  
pp. 823-826
Author(s):  
G.Sh. Hovsepyan ◽  
M.A. Kalantaryan ◽  
T.V. Yedoyan
Keyword(s):  
Experimental Data ◽  
Surface Modification ◽  
Sorption Capacity ◽  
Water Sorption ◽  
Structural Changes ◽  
Ir Spectrometry ◽  
Water Capacity ◽  
Series Of Experiments ◽  
Water Sorption Capacity

The aim of this paper is to study the possibility of expanded obsidian and its modified product use for oil sorption, in that tetraethoxisilane (TEOS) has been used as a modifier. The optimal concentration of the modifier was determined by 50 per cent weight of expanded obsidian. The expanded obsidian was previously activated with 0,1 M solution of hydrochloric acid. IR spectrometry was used to characterise structural changes in the modified expanded obsidian samples. To determine water sorption capacity a series of experiments has been carried out. The analysis of obtained experimental data showed that after surface modification of expanded obsidian water capacity is reduced 3 times after the surface modification of EO.

Wave Height Measurements Behind Submerged Lens-Shaped Structures

2011 ◽  
Author(s):  
Andrew L. Bloxom ◽  
Karl D. von Ellenrieder ◽  
Matthew R. Anderson ◽  
Ryan S. Mieras ◽  
William S. Weidle
Keyword(s):  
Wave Height ◽  
Focal Point ◽  
Focal Length ◽  
Experimental Tests ◽  
Geometrical Optics ◽  
Width Ratio ◽  
Focal Points ◽  
Wave Amplification ◽  
Strip Theory ◽  
Longitudinal Position

The ability of submerged lens-shaped structures to focus linear surface waves in deep water is explored through a series of experimental tests in a wave making basin. Three lenses were designed using a combination of linear strip theory and a surface wave analogy to geometrical optics. Two of these lenses were designed to focus waves of a single wavelength of 0.482 m (18.97 in.), one with a focal length to lens width ratio (f-number) of 2.0 and the other with an f-number of 0.5. The third lens was designed to function as a compound lens that could focus a range of wavelengths of between 0.39 m (15.37 in.) and 0.694 m (27.32 in.) at an f-number of 2.0. Using resistance wave height gauges, the sensitivity of wave height at the focus to variations in wavelength from between 0.39 m (15.37 in.) to 0.61 m (24.01 in.) was experimentally measured for all three lenses; the sensitivity of wave height at the focus to variations of lens depths of submergence spanning the range of between 0.75 to 1.25 times the design submergence depth was also explored for the two simple lenses. It was found that the linear strip theory and geometrical optics approach predicted the wave amplification to within ten percent at the design wavelengths and depths, but that the longitudinal position of the experimentally observed focal lengths differed substantially from that expected, by as much as a factor of 2.2 for an f-number of 0.5. Additionally, while the theory predicted a single focal point for each lens, multiple focal points were found to exist behind the compound lens.

A New Methodology for Generation of Solitary Water Waves in Laboratory

2020 ◽  
Author(s):  
Xiao Liu ◽  
Yong Liu
Keyword(s):  
Solitary Wave ◽  
Wave Height ◽  
Water Waves ◽  
Particle Image ◽  
Fluid Velocity ◽  
Simple System ◽  
Wave Surface ◽  
Wave Flume ◽  
Image Velocimetry ◽  
Laboratory Flume

Abstract In this article, a very simple system based on the enhanced dam-break flows was proposed and implemented to generate solitary wave with larger relative wave height (the ratio of wave height to water depth) in a laboratory flume. The experimental results showed that stable waves with the solitary wave profiles were successfully generated in the wave flume. The wave surface elevations were recorded by a series of wave gauges, and the fluid velocity field of the solitary wave was measured by Particle Image Velocimetry (PIV) system. The measurements of solitary wave profile, celerity and horizontal fluid velocity were also compared with the predictions by three different solitary wave theories. Results demonstrated that the present simple system was reliable and effective for the generation of solitary waves in laboratory.

LARGE SCALE EXPERIMENTS ON EVOLUTION AND RUN-UP OF BREAKING SOLITARY WAVES

2007 ◽  
Vol 01 (03) ◽  
pp. 257-272 ◽  
Author(s):  
KAO-SHU HWANG ◽  
YU-HSUAN CHANG ◽  
HWUNG-HWENG HWUNG ◽  
YI-SYUAN LI
Keyword(s):  
Solitary Wave ◽  
Wave Height ◽  
Solitary Waves ◽  
Water Depth ◽  
Large Scale ◽  
Scale Effects ◽  
Wave Heights ◽  
Run Up ◽  
Hydraulics Laboratory ◽  
The Waves

The evolution and run-up of breaking solitary waves on plane beaches are investigated in this paper. A series of large-scale experiments were conducted in the SUPER TANK of Tainan Hydraulics Laboratory with three plane beaches of slope 0.05, 0.025 and 0.017 (1:20, 1:40 and 1:60). Solitary waves of which relative wave heights, H/h0, ranged from 0.03 to 0.31 were generated by two types of wave-board displacement trajectory: the ramp-trajectory and the solitary-wave trajectory proposed by Goring (1979). Experimental results show that under the same relative wave height, the waveforms produced by the two generation procedures becomes noticeably different as the waves propagate prior to the breaking point. Meanwhile, under the same relative wave height, the larger the constant water depth is, the larger the dimensionless run-up heights would be. Scale effects associated with the breaking process are discussed.

Assessment of the wave attenuation capacity of a mangrove forest based on its age and the incident wave conditions

2020 ◽  
Author(s):  
Maria Maza ◽  
Javier L. Lara ◽  
Iñigo J. Losada
Keyword(s):  
Wave Height ◽  
Water Depth ◽  
Mangrove Forest ◽  
Wave Attenuation ◽  
Volume Fraction ◽  
Coastal Protection ◽  
Local Flow ◽  
Ecosystem Properties ◽  
Wave Decay ◽  
Wave Conditions

<p>Although mangroves reduce annual flooding to millions of people there is not a methodology to implement these solutions and it is still difficult to estimate the protection provided by them under different environmental conditions and ecosystem properties. To move forward in the consecution of an engineering approach when implementing these solutions for coastal defense, the first step to make is to better understand and parameterize the basic physical processes involved in flow-mangroves interaction. With the aim of getting a new formulation for wave decay provided by Rhizophora mangrove forests based on flow and ecosystem properties, an experimental campaign was carried out where both wave attenuation and forces on mangrove individuals were measured under different wave conditions. Both, the hydrodynamic conditions and the mangrove forest, were scaled according to field conditions for short waves. The detailed wave attenuation and drag force measurements obtained in these experiments allowed to obtain new formulations of wave decay produced by the forest depending on the flow, i.e.: water depth, wave height and period, and on the forest characteristics, i.e.: individuals submerged solid volume fraction and density. These formulations are used to get attenuation rates under different flow and ecosystem conditions. The resultant curves provide with the wave decay produced by a specific Rhizophora forest subjected to the defined wave conditions. The forest is defined on the basis of its age, considering the differences in individual trees depending on their maturity and the density of the forest as the number of trees per unit area. Wave conditions are defined by the root mean square wave height and the peak period and water depth is also considered. The obtained curves allow to estimate the width of the forest necessary to reach a certain level of protection considering the local flow conditions and the forest age. This can assist in the inclusion of nature-based solutions in the portfolio of coastal protection measures.</p>

Numerical and Experimental Investigations of Wave Field Around a Circular Island with the Presence of Weak Currents

2002 ◽  
Vol 18 (1) ◽  
pp. 35-42
Author(s):  
Ming-Chung Lin ◽  
Chao-Min Hsu ◽  
Shou-Cheng Wang ◽  
Chao-Lung Ting
Keyword(s):  
Experimental Data ◽  
Wave Field ◽  
Wave Height ◽  
Incident Wave ◽  
Numerical Calculations ◽  
Experimental Investigations ◽  
Wave Refraction ◽  
Circular Island ◽  
Incident Waves ◽  
A Current

ABSTRACTThis study elucidated the complicated phenomena of wave refraction and diffraction around a circular island due to random incident waves traveling with a current. Various combinations of random incident wave and current conditions were used to investigate the wave height distributions around a circular island numerically and experimentally. Numerical calculations were carried out based on the theory derived by Lin & Hsu [1]. According to the results, it shows that numerical calculations can predict experimental data quantitatively well.

Modeling the sloshing problem in a rectangular tank with submerged incomplete baffles

2016 ◽  
Vol 26 (3/4) ◽  
pp. 722-744 ◽  
Author(s):  
Marcela A. Cruchaga ◽  
Carlos Ferrada ◽  
Nicolás Márquez ◽  
Sebastián Osses ◽  
Mario Storti ◽  
...  
Keyword(s):  
Experimental Data ◽  
Free Surface ◽  
Wave Height ◽  
Numerical Study ◽  
Free Surface Flows ◽  
Numerical Results ◽  
Surface Evolution ◽  
Content Type ◽  
Near Resonance ◽  
Wave Heights

Purpose – The present work is an experimental and numerical study of a sloshing problem including baffle effects. The purpose of this paper is to assess the numerical behavior of a Lagrangian technique to track free surface flows by comparison with experiments, to report experimental data for sloshing at different conditions and to evaluate the effectiveness of baffles in limiting the wave height and the wave propagation. Design/methodology/approach – Finite element simulations performed with a fixed mesh technique able to describe the free surface evolution are contrasted with experimental data. The experiments consist of an acrylic tank of rectangular section designed to attach baffles of different sizes at different distance from the bottom. The tank is filled with water and mounted on a shake table able to move under controlled horizontal motion. The free surface evolution is measured with ultrasonic sensors. The numerical results computed for different sloshing conditions are compared with the experimental data. Findings – The reported numerical results are in general in good agreement with the experiments. In particular, wave heights and frequencies response satisfactorily compared with the experimental data for the several cases analyzed during steady state forced sloshing and free sloshing. The effectiveness of the baffles increases near resonance conditions. From the set of experiments studied, the major reduction of the wave height was obtained when larger baffles were positioned closer to the water level at rest. Practical implications – Model validation: evaluation of the effectiveness of non-massive immersed baffles during sloshing. Originality/value – The value of the present work encompass the numerical and experimental study of the effect of immersed baffles during sloshing under different imposed conditions and the comparison of numerical results with the experimental data. Also, the results shown in the present work are a contribution to the understanding of the role in the analysis of the proposed problem of some specific aspects of the geometry and the imposed motion.

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