scholarly journals BOTTOM DISSIPATION IN FINITE-DEPTH WATER WAVES

1978 ◽  
Vol 1 (16) ◽  
pp. 24 ◽  
Author(s):  
S.V. Hsiao ◽  
O.H. Shemdin
Keyword(s):  
Friction Coefficient ◽  
Shallow Water ◽  
Wave Energy ◽  
Water Waves ◽  
Field Measurements ◽  
Finite Depth ◽  
Bottom Friction ◽  
Friction Mechanism ◽  
Spectral Transformation ◽  
Depth Water

The dissipation of wave energy by various bottom mechanisms plays an important role in the spectral transformation of waves as they propagate from deep to shallow water. Three bottom dissipation mechanisms are discussed. The bottom friction mechanism is investigated in detail and a method for calculating the friction coefficient is proposed. The method is tested by comparison with field measurements. Dissipation due to percolation and bottom motion are also discussed. The magnitude of dissipation rates induced by the different mechanisms are compared under various wave and bottom conditions.

scholarly journals SHALLOW WATER WAVES: A SPECTRAL APPROACH

1984 ◽  
Vol 1 (19) ◽  
pp. 26 ◽  
Author(s):  
Charles L. Vincent
Keyword(s):  
Shallow Water ◽  
Water Waves ◽  
Surf Zone ◽  
Finite Depth ◽  
Wave Transformation ◽  
Shallow Water Waves ◽  
Self Similar ◽  
Wind Sea ◽  
Spectral Equation ◽  
Depth Water

Bouws et al. (1983, 1984) have shown that wind sea spectra in finite depth water can be described by a self-similar spectral equation that in the deep water limit is the JONSWAP spectrum (Hasselmann et al. 1973). This paper shows that the spectral parameter a is linked to wave steepness, for wind sea and swell; presents a simple model for wave transformation across the surf zone; and shows that the spectral theory provides data similar to the results of Bretschneider (1958) for shallow water wave growth.

scholarly journals EVALUATION OF SEAGRASS AS A WAVE ENERGY DISSIPATION ELEMENT

2012 ◽  
Vol 1 (33) ◽  
pp. 17
Author(s):  
Edgar Mendoza ◽  
Jose Hoil ◽  
Rodolfo Silva ◽  
Cecilia Enriquez
Keyword(s):  
Energy Dissipation ◽  
Shallow Water ◽  
Wave Energy ◽  
Bottom Friction ◽  
Coastal Protection ◽  
Sediment Stability ◽  
Sea Floor ◽  
Wave Energy Dissipation ◽  
Disturbed Areas ◽  
Depth Reduction

In shallow water, particularly near the coast, the hydrodynamics are influenced by bottom friction which, increases with depth reduction and the complexity of the sea floor, mostly in the presence of vegetation. Although little is still known about the seagrass capability to reduce wave energy, it is known to increase the sediment stability in anthropogenically disturbed areas; hence the interest of evaluating their efficiency as a means for coastal protection.

scholarly journals The "shallow-waterness" of the wave climate in European coastal regions

2016 ◽  
Author(s):  
Kai Håkon Christensen ◽  
Ana Carrasco ◽  
Jean-Raymond Bidlot ◽  
Øyvind Breivik
Keyword(s):  
Shallow Water ◽  
Deep Water ◽  
Wave Energy ◽  
Water Waves ◽  
Bottom Topography ◽  
Mean Flow ◽  
Momentum Exchange ◽  
Shallow Water Waves ◽  
Coastal Regions ◽  
Deep Water Waves

Abstract. In contrast to deep water waves, shallow water waves are influenced by bottom topography, which has consequences for the propagation of wave energy as well as for the energy and momentum exchange between the waves and the mean flow. The ERA-Interim reanalysis is used to assess the fraction of wave energy associated with shallow water waves in coastal regions in Europe. We show maps of the distribution of this fraction as well as time series statistics from 8 selected stations. There is a strong seasonal dependence and high values are typically associated with winter storms, indicating that shallow water wave effects can occasionally be important even in the deeper parts of the shelf seas otherwise dominated by deep water waves.

Scattering of water waves by inclined thin plate submerged in finite-depth water

2001 ◽  
Vol 71 (12) ◽  
pp. 827-840 ◽  
Author(s):  
Ch. Midya ◽  
M. Kanoria ◽  
B. N. Mandal
Keyword(s):  
Thin Plate ◽  
Water Waves ◽  
Finite Depth ◽  
Depth Water

Experimental Study on Spatial Variation of Mass Transport Induced by Surface Waves Generated in a Finite-Depth Laboratory Flume

2020 ◽  
Vol 50 (12) ◽  
pp. 3501-3511
Author(s):  
Maciej Paprota
Keyword(s):  
Mass Transport ◽  
Shallow Water ◽  
Ocean Circulation ◽  
Water Waves ◽  
Laboratory Data ◽  
Finite Depth ◽  
Experimental Investigations ◽  
Valuable Insight ◽  
Numerical Predictions ◽  
Wave Induced

AbstractThe aim of laboratory experiments conducted in a wave flume is to confirm that wave-induced mass transport varies along the way of propagation of regular mechanically generated waves in water of finite depth. This effect is attributed to the interactions between primary waves generated in the flume and associated free waves. Measurements of wave kinematics in several locations along the flume are performed to evaluate mass transport. Wave gauges and the particle image velocimetry technique are employed, respectively, to provide information on the evolution of the oscillating water surface and the wave velocity field under regular waves. Laboratory data are compared with numerical predictions of the derived nonlinear wavemaker model based on a pseudospectral approach. The experimental data exhibit good agreement with the numerical results with respect to particle trajectories and mass transport for nonlinear transitional and shallow water waves. Numerical and experimental investigations confirm that free-surface oscillatory motion and particle kinematics are affected by second-order free waves, which modify the characteristics of laboratory waves, especially in a strongly nonlinear shallow water regime. Moreover, the present study gives valuable insight into the effects of the interaction between two independent waves on wave-induced mass transport, which highlights the need of including nonlinear energy transfers between higher harmonics for the reliable estimation of wave processes in ocean circulation models.

Radiation and diffraction by a submerged sphere advancing in water waves of finite depth

1995 ◽  
Vol 448 (1932) ◽  
pp. 29-54 ◽  
Keyword(s):  
Water Waves ◽  
Finite Depth ◽  
Multipole Expansion ◽  
The Body ◽  
Field Equations ◽  
Damping Coefficients ◽  
Submerged Sphere ◽  
Added Masses ◽  
Exciting Forces ◽  
Depth Water

A submerged sphere advancing in a regular finite depth water wave at constant forward speed is analysed by linearized velocity potential. The solution is ob­tained by the multipole expansion extended from that developed for zero speed. Numerical results are obtained for wave-making resistance and lift, added masses, damping coefficients and exciting forces. Far field equations are also derived for calculating damping coefficients and exciting forces. They are used to check the results obtained from integrating pressure over the body surface. Excellent agree­ment is found.

scholarly journals The “shallow-waterness” of the wave climate in European coastal regions

Ocean Science ◽  
2017 ◽  
Vol 13 (4) ◽  
pp. 589-597
Author(s):  
Kai Håkon Christensen ◽  
Ana Carrasco ◽  
Jean-Raymond Bidlot ◽  
Øyvind Breivik
Keyword(s):  
Shallow Water ◽  
Deep Water ◽  
Wave Energy ◽  
Water Waves ◽  
Bottom Topography ◽  
Mean Flow ◽  
Momentum Exchange ◽  
Shallow Water Waves ◽  
Coastal Regions ◽  
Deep Water Waves

Abstract. In contrast to deep water waves, shallow water waves are influenced by bottom topography, which has consequences for the propagation of wave energy as well as for the energy and momentum exchange between the waves and the mean flow. The ERA-Interim reanalysis is used to assess the fraction of wave energy associated with shallow water waves in coastal regions in Europe. We show maps of the distribution of this fraction as well as time series statistics from eight selected stations. There is a strong seasonal dependence and high values are typically associated with winter storms, indicating that shallow water wave effects can occasionally be important even in the deeper parts of the shelf seas otherwise dominated by deep water waves.

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