scholarly journals Characterizing Wave Shape Evolution on an Ebb-Tidal Shoal

2019 ◽  
Vol 7 (10) ◽  
pp. 367 ◽  
Author(s):  
Floris de Wit ◽  
Marion Tissier ◽  
Ad Reniers
Keyword(s):  
Wave Breaking ◽  
Field Measurements ◽  
Tidal Currents ◽  
Wave Shape ◽  
Spatial Gradients ◽  
Nonlinear Energy Transfer ◽  
Waves And Currents ◽  
Wave Induced ◽  
Local Parameters ◽  
Nonlinear Energy

Field measurements of waves and currents were obtained at ten locations on an ebb-tidal shoal seaward of Ameland Inlet for a six-week period. These measurements were used to investigate the evolution of the near-bed velocity skewness and asymmetry, as these are important drivers for wave-induced sediment tranport. Wave shape parameters were compared to traditionally used parameterizations to quantify their performance in a dynamic area with waves and tidal currents coming in from different directions over a highly variable bathymetry. Spatially and temporally averaged, these parameterizations compared very well to observed wave shape. However, significant scatter was observed. The largest deviations from the parameterization were observed at the shallowest locations, where the contribution of wave-induced sediment transport was expected to be the largest. This paper shows that this scatter was caused by differences in wave-breaking, nonlinear energy transfer rate, and spatial gradients in tidal currents. Therefore, it is proposed to include the prior evolution of the wave before reaching a location in future parameterizations in numerical modeling instead of only using local parameters to predict wave shape.

Frequency spectra evolution of two-dimensional focusing wave groups in finite depth water

2011 ◽  
Vol 688 ◽  
pp. 169-194 ◽  
Author(s):  
Zhigang Tian ◽  
Marc Perlin ◽  
Wooyoung Choi
Keyword(s):  
Energy Transfer ◽  
Wave Breaking ◽  
Frequency Region ◽  
Breaking Wave ◽  
Two Dimensional ◽  
Spectral Bandwidth ◽  
Frequency Spectra ◽  
Wave Groups ◽  
Nonlinear Energy Transfer ◽  
Nonlinear Energy

AbstractAn experimental and numerical study of the evolution of frequency spectra of dispersive focusing wave groups in a two-dimensional wave tank is presented. Investigations of both non-breaking and breaking wave groups are performed. It is found that dispersive focusing is far more than linear superposition, and that it undergoes strongly nonlinear processes. For non-breaking wave groups, as the wave groups propagate spatial evolution of wave frequency spectra, spectral bandwidth, surface elevation skewness, and kurtosis are examined. Nonlinear energy transfer between the above-peak ($f/ {f}_{p} = 1. 2{{\ndash}}1. 5$) and the higher-frequency ($f/ {f}_{p} = 1. 5\text{{\ndash}} 2. 5$) regions, with ${f}_{p} $ being the spectral peak frequency, is demonstrated by tracking the energy level of the components in the focusing and defocusing process. Also shown is the nonlinear energy transfer to the lower-frequency components that cannot be detected easily by direct comparisons of the far upstream and downstream measurements. Energy dissipation in the spectral peak region ($f/ {f}_{p} = 0. 9\text{{\ndash}} 1. 1$) and the energy gain in the higher-frequency region ($f/ {f}_{p} = 1. 5\text{{\ndash}} 2. 5$) are quantified, and exhibit a dependence on the Benjamin–Feir Index (BFI). In the presence of wave breaking, the spectral bandwidth reduces as much as 40 % immediately following breaking and eventually becomes much smaller than its initial level. Energy levels in different frequency regions are examined. It is found that, before wave breaking onset, a large amount of energy is transferred from the above-peak region ($f/ {f}_{p} = 1. 2\text{{\ndash}} 1. 5$) to the higher frequencies ($f/ {f}_{p} = 1. 5\text{{\ndash}} 2. 5$), where energy is dissipated during the breaking events. It is demonstrated that the energy gain in the lower-frequency region is at least partially due to nonlinear energy transfer prior to wave breaking and that wave breaking may not necessarily increase the energy in this region. Complementary numerical studies for breaking waves are conducted using an eddy viscosity model previously developed by the current authors. It is demonstrated that the predicted spectral change after breaking agrees well with the experimental measurements.

scholarly journals Evaluation of Spatial Variation of Nonlinear Energy Transfer by Use of Turbulence Diagnostic Simulator

2013 ◽  
Vol 8 (0) ◽  
pp. 2403070-2403070 ◽  
Author(s):  
Naohiro KASUYA ◽  
Satoru SUGITA ◽  
Makoto SASAKI ◽  
Shigeru INAGAKI ◽  
Masatoshi YAGI ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Spatial Variation ◽  
Nonlinear Energy Transfer ◽  
Nonlinear Energy

scholarly journals Development of an analytical model to predict oil reservoirs performance using mechanical waves propagation

2021 ◽  
Author(s):  
Hesham A. Abu Zaid ◽  
◽  
Sherif A. Akl ◽  
Mahmoud Abu El Ela ◽  
Ahmed El-Banbi ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Field Measurements ◽  
Field Trials ◽  
Oil Field ◽  
Reservoir Properties ◽  
Actual Performance ◽  
Reservoir Performance ◽  
Mechanical Waves ◽  
Incremental Oil Recovery ◽  
Wave Induced

The mechanical waves have been used as an unconventional enhanced oil recovery technique. It has been tested in many laboratory experiments as well as several field trials. This paper presents a robust forecasting model that can be used as an effective tool to predict the reservoir performance while applying seismic EOR technique. This model is developed by extending the wave induced fluid flow theory to account for the change in the reservoir characteristics as a result of wave application. A MATLAB program was developed based on the modified theory. The wave’s intensity, pressure, and energy dissipation spatial distributions are calculated. The portion of energy converted into thermal energy in the reservoir is assessed. The changes in reservoir properties due to temperature and pressure changes are considered. The incremental oil recovery and reduction in water production as a result of wave application are then calculated. The developed model was validated against actual performance of Liaohe oil field. The model results show that the wave application increases oil production from 33 to 47 ton/day and decreases water-oil ratio from 68 to 48%, which is close to the field measurements. A parametric analysis is performed to identify the important parameters that affect reservoir performance under seismic EOR. In addition, the study determines the optimum ranges of reservoir properties where this technique is most beneficial.

scholarly journals Influence of Accuracy Improvement of Nonlinear Energy Transfer in Wave Model

2009 ◽  
Vol 65 (1) ◽  
pp. 171-175
Author(s):  
Noriaki HASHIMOTO ◽  
Koji KAWAGUCHI ◽  
Katsuyuki SUZUYAMA ◽  
Masaru YAMASHIRO ◽  
Mitsuyoshi KODAMA
Keyword(s):  
Energy Transfer ◽  
Wave Model ◽  
Accuracy Improvement ◽  
Nonlinear Energy Transfer ◽  
Nonlinear Energy

scholarly journals Nonlinear couplings and energy transfers in micro- and nano-mechanical resonators: intermodal coupling, internal resonance and synchronization

2018 ◽  
Vol 376 (2127) ◽  
pp. 20170141 ◽  
Author(s):  
Keivan Asadi ◽  
Jun Yu ◽  
Hanna Cho
Keyword(s):  
Internal Resonance ◽  
Development Stage ◽  
Vibrational Modes ◽  
Mechanical Resonators ◽  
The Past ◽  
Nonlinear Energy Transfer ◽  
Energy Transfers ◽  
Wide Range ◽  
Plate Type ◽  
Nonlinear Energy

Extensive development of micro/nano-electromechanical systems (MEMS/NEMS) has resulted in technologies that exhibit excellent performance over a wide range of applications in both applied (e.g. sensing, imaging, timing and signal processing) and fundamental sciences (e.g. quantum-level problems). Many of these outstanding applications benefit from resonance phenomena by employing micro/nanoscale mechanical resonators often fabricated into a beam-, membrane- or plate-type structure. During the early development stage, one of the vibrational modes (typically the fundamental mode) of a resonator is considered in the design and application. In the past decade, however, there has been a growing interest in using more than one vibrational mode for the enhanced functionality of MEMS/NEMS. In this paper, we review recent research efforts to investigate the nonlinear coupling and energy transfers between multiple modes in micro/nano-mechanical resonators, focusing especially on intermodal coupling, internal resonance and synchronization. This article is part of the theme issue ‘Nonlinear energy transfer in dynamical and acoustical systems’.

scholarly journals WAVE-INDUCED SHOCK PRESSURES UNDER REAL SEA STATE CONDITIONS

1988 ◽  
Vol 1 (21) ◽  
pp. 173 ◽  
Author(s):  
Joachim Grune
Keyword(s):  
Peak Pressure ◽  
Field Measurements ◽  
Breaking Waves ◽  
Sea State ◽  
Pressure Time ◽  
Time Histories ◽  
Wave Induced

This paper deals with a study on shock pressures, which occur on sloping seadykes and revetments due to breaking waves. Results from field measurements are presented with respect to peak pressure values as well as to characteristics of pressure-time histories.

Numerical Simulation of Wave Breaking Over a Submerged Step with SPH Method

2018 ◽  
Vol 01 (02) ◽  
pp. 1840005 ◽  
Author(s):  
Hongjie Wen ◽  
Bing Ren ◽  
Guoyu Wang ◽  
Yumeng Zhao
Keyword(s):  
Wave Breaking ◽  
Sph Method ◽  
Vertical Distributions ◽  
Sph Model ◽  
Smoothed Particle ◽  
Mean Water Level ◽  
The Mean ◽  
Wave Maker ◽  
Wave Induced ◽  
Smoothed Particle Hydrodynamic

Wave breaking over a submerged step with a steep front slope and a wide horizontal platform is studied by smoothed particle hydrodynamic (SPH) method. By adding a momentum source term and a velocity attenuation term into the governing equation, a nonreflective wave maker system is introduced in the numerical model. A suitable circuit channel is specifically designed for the present SPH model to avoid the nonphysical rise of the mean water level on the horizontal platform of the submerged step. The predicted free surface elevations and the spatial distributions of wave height and wave setup over the submerged step are validated using the corresponding experimental data. In addition, the vertical distributions of wave-induced current over the submerged step are also investigated at both low and high tides.

scholarly journals Abyssal plain hills and internal wave turbulence

2018 ◽  
Vol 15 (14) ◽  
pp. 4387-4403 ◽  
Author(s):  
Hans van Haren
Keyword(s):  
Internal Wave ◽  
Wave Breaking ◽  
Large Scale ◽  
Abyssal Plain ◽  
Marginal Stability ◽  
Eddy Diffusivities ◽  
North East ◽  
Mid Atlantic Ridge ◽  
Ocean Topography ◽  
Wave Induced

Abstract. A 400 m long array with 201 high-resolution NIOZ temperature sensors was deployed above a north-east equatorial Pacific hilly abyssal plain for 2.5 months. The sensors sampled at a rate of 1 Hz. The lowest sensor was at 7 m above the bottom (m a.b.). The aim was to study internal waves and turbulent overturning away from large-scale ocean topography. Topography consisted of moderately elevated hills (a few hundred metres), providing a mean bottom slope of one-third of that found at the Mid-Atlantic Ridge (on 2 km horizontal scales). In contrast with observations over large-scale topography like guyots, ridges and continental slopes, the present data showed a well-defined near-homogeneous “bottom boundary layer”. However, its thickness varied strongly with time between < 7 and 100 m a.b. with a mean around 65 m a.b. The average thickness exceeded tidal current bottom-frictional heights so that internal wave breaking dominated over bottom friction. Near-bottom fronts also varied in time (and thus space). Occasional coupling was observed between the interior internal wave breaking and the near-bottom overturning, with varying up- and down- phase propagation. In contrast with currents that were dominated by the semidiurnal tide, 200 m shear was dominant at (sub-)inertial frequencies. The shear was so large that it provided a background of marginal stability for the straining high-frequency internal wave field in the interior. Daily averaged turbulence dissipation rate estimates were between 10−10 and 10−9 m2 s−3, increasing with depth, while eddy diffusivities were of the order of 10−4 m2 s−1. This most intense “near-bottom” internal-wave-induced turbulence will affect the resuspension of sediments.

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