scholarly journals MODE AND PERIOD OF SAND TRANSPORT IN THE SURF ZONE

1974 ◽  
Vol 1 (14) ◽  
pp. 47 ◽  
Author(s):  
Benno M. Brenninkmeyer
Keyword(s):  
Deep Water ◽  
Water Wave ◽  
Surf Zone ◽  
Sediment Concentration ◽  
Sand Transport ◽  
Bed Load ◽  
Measuring Devices ◽  
Load Movement ◽  
Sand Movement ◽  
Deep Water Wave

Three almometers-water opacity measuring devices-emplaced perpendicular to the beach, measure instantaneously and continuously the sediment concentration across the surf zone. Most of the variance of the sand movement is centered in frequencies of less than 0.25 Hz and between 1.15 and 1.25 Hz. Modes and frequency of sand transport differ within each of the dynamic zones of the surf. The motion of sediment in the inner and outer surf zones is small and virtually independent of the deep water wave periods. Outside the breaker zone, bed load movement is somewhat coincident with the prevailing swell period. Lighter concentrations move predominantly with a 0.8-0.9 second periodicity. In the breaker zone, sand moves along the bottom with frequencies equal to that of both the swell and sea, but most of the power is in lower frequencies. In the breaker zone sand is rarely thrown into suspension. In the transition zone, sediment motion is largely by suspension with a period a little longer than the swell.

scholarly journals SEDIMENT TRANSPORT DUE TO BREAKING WAVES

1986 ◽  
Vol 1 (20) ◽  
pp. 111 ◽  
Author(s):  
Tomoya Shibayama ◽  
Akihiko Higuchi ◽  
Kiyoshi Horikawa
Keyword(s):  
Water Wave ◽  
Surf Zone ◽  
Breaking Waves ◽  
Wave Flume ◽  
Suspension Process ◽  
Large Vortex ◽  
Sand Movement ◽  
Bed Materials ◽  
Deep Water Wave ◽  
Two Parameters

In the surf zone, the agitation of the bed materials by breaking waves is strong and the suspended sand concentration in the vicinity of the wave plunging point is extremely high. Sand movement in this region was observed and sand concentration was measured in a wave flume. The sand movement in the region was divided into the following two categories: 1) sand suspension due to the large vortex which is created by wave plunging, and 2) sand deposition under turbulent flow. The condition for exciting this suspension process was considered and the result was well explained by the two parameters which are the deep water wave steepness and the bottom slope. Then a numerical model of the sediment suspension process was formulated and the process was well simulated by the model.

scholarly journals Computational Fluid Dynamics Simulation of Deep-Water Wave Instabilities Involving Wave Breaking

2021 ◽  
Vol 144 (2) ◽  
Author(s):  
Yuzhu Li ◽  
David R. Fuhrman
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Deep Water ◽  
Wave Breaking ◽  
Water Wave ◽  
Class Ii ◽  
Dynamics Simulation ◽  
Class I ◽  
Wave Instabilities ◽  
Deep Water Wave

Abstract Instabilities of deep-water wave trains subject to initially small perturbations (which then grow exponentially) can lead to extreme waves in offshore regions. The present study focuses on the two-dimensional Benjamin–Feir (or modulational) instability and the three-dimensional crescent (or horseshoe) waves, also known as Class I and Class II instabilities, respectively. Numerical studies on Class I and Class II wave instabilities to date have been mostly limited to models founded on potential flow theory; thus, they could only properly investigate the process from initial growth of the perturbations to the initial breaking point. The present study conducts numerical simulations to investigate the generation and development of wave instabilities involving the wave breaking process. A computational fluid dynamics (CFD) model solving Reynolds-averaged Navier–Stokes (RANS) equations coupled with a turbulence closure model in terms of the Reynolds stress model is applied. Wave form evolutions, Fourier amplitudes, and the turbulence beneath the broken waves are investigated.

Laboratory Observations on the Evolution of Deep-Water Wave Packets

2011 ◽  
Author(s):  
Yuxiang Ma ◽  
Guohai Dong ◽  
Xiaozhou Ma
Keyword(s):  
Experimental Data ◽  
Deep Water ◽  
Wave Breaking ◽  
Water Wave ◽  
Wave Packets ◽  
Local Maximum ◽  
Peak Frequency ◽  
Higher Harmonics ◽  
Stokes Waves ◽  
Deep Water Wave

New experimental data for the evolution of deep-water wave packets has been presented. The present experimental data shows that the local maximum steepness for extreme waves is significantly above the criterion of the limiting Stokes waves. The wavelet spectra of the wave groups around the breaking locations indicate that the energy of higher harmonics can be generated quickly before wave breaking and mainly concentrate at the part of the wave fronts. After wave breaking, however, these higher harmonics energy is dissipated immediately. Furthermore, the variations of local peak frequency have also been examined. It is found that frequency downshift increases with the increase of initial steepness and wave packet size.

scholarly journals Experimental Realization of Periodic Deep-Water Wave Envelopes with and without Dissipation

Water Waves ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 113-122 ◽  
Author(s):  
M. Magnani ◽  
M. Onorato ◽  
D. Gunn ◽  
M. Rudman ◽  
B. Kibler ◽  
...  
Keyword(s):  
Deep Water ◽  
Water Wave ◽  
Experimental Realization ◽  
Deep Water Wave
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