Numerical Calculation of Wind Waves in Shallow Water

1967 ◽  
Author(s):  
Takeshi Ijima ◽  
Frederick L. W. Tang
Keyword(s):  
Numerical Calculation ◽  
Shallow Water ◽  
Wind Waves

scholarly journals Random wave-driven drag forces on near-bed vegetation in shallow water based on deepwater wind conditions

2019 ◽  
Vol 233 (4) ◽  
pp. 1287-1290
Author(s):  
Dag Myrhaug
Keyword(s):  
Shallow Water ◽  
Drag Force ◽  
Wind Waves ◽  
Wave Spectrum ◽  
Random Wave ◽  
Random Waves ◽  
Coastal Zones ◽  
Drag Forces ◽  
Mean Wind Speed ◽  
Wave Induced

This article provides a simple analytical method for giving estimates of random wave-driven drag forces on near-bed vegetation in shallow water from deepwater wind conditions. Results are exemplified using a Pierson–Moskowitz model wave spectrum for wind waves with the mean wind speed at the 10 m elevation above the sea surface as the parameter. The significant value of the drag force within a sea state of random waves is given, and an example typical for field conditions is presented. This method should serve as a useful tool for assessing random wave-induced drag force on vegetation in coastal zones and estuaries based on input from deepwater wind conditions.

Effects of wind waves on horizontal array performance in shallow-water conditions

2017 ◽  
Vol 63 (5) ◽  
pp. 542-552 ◽  
Author(s):  
N. A. Zavol’skii ◽  
A. I. Malekhanov ◽  
M. A. Raevskii ◽  
A. V. Smirnov
Keyword(s):  
Shallow Water ◽  
Wind Waves ◽  
Water Conditions ◽  
Array Performance ◽  
Horizontal Array

scholarly journals Wave Forecasting in Shallow Water: A New Set of Growth Curves Depending on Bed Roughness

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2313 ◽  
Author(s):  
Sara Pascolo ◽  
Marco Petti ◽  
Silvia Bosa
Keyword(s):  
Shallow Water ◽  
Field Experiments ◽  
Wind Waves ◽  
Growth Curves ◽  
Initial Attempt ◽  
Wave Data ◽  
Broad Variety ◽  
Variable Roughness ◽  
Bed Roughness ◽  
Wave Forecasting

Forecasting relationships have been recognized as an important tool to be applied together, or not, with complete numerical modelling in order to reconstruct the wave field in coastal areas properly when the available wave data is limited. In recent years, the literature has offered several comprehensive sets of field experiments investigating the form of the asymptotic, depth-limited wind waves. This has made it possible to reformulate the original deep water equations, taking into account the effects of water depth, if wind waves are locally generated in shallow and confined basins. The present paper is an initial attempt to further contribute to the shallow water forecasting curves which are currently available, also considering the role on the wave generation of a variable equivalent bottom roughness. This can offer the possibility of applying shallow growth curves to a broad variety of contexts, for which bed composition and forms can be different. Simple numerical tests have been conducted to reproduce the fully developed conditions of wave motion with variable roughness values. To validate the new set of equations, they have been applied to a real shallow lake for which both experimental and numerical wave data is available. The comparison of the obtained results is very encouraging in proceeding with this approach.

scholarly journals Soliton spectra of random water waves in shallow basins

2018 ◽  
Vol 13 (4) ◽  
pp. 40 ◽  
Author(s):  
J.-P. Giovanangeli ◽  
C. Kharif ◽  
Y.A. Stepanyants
Keyword(s):  
Shallow Water ◽  
Wave Field ◽  
Water Waves ◽  
Wind Waves ◽  
Inverse Scattering Method ◽  
Random Wave ◽  
Scattering Method ◽  
Wave Fields ◽  
Fourier Spectra ◽  
Random Wave Field

Interpretation of random wave field on a shallow water in terms of Fourier spectra is not adequate, when wave amplitudes are not infinitesimally small. A nonlinearity of wave fields leads to the harmonic interactions and random variation of Fourier spectra. As has been shown by Osborne and his co-authors, a more adequate analysis can be performed in terms of nonlinear modes representing cnoidal waves; a spectrum of such modes remains unchanged even in the process of nonlinear mode interactions. Here we show that there is an alternative and more simple analysis of random wave fields on shallow water, which can be presented in terms of interacting Korteweg–de Vries solitons. The data processing of random wave field is developed on the basis of inverse scattering method. The soliton component obscured in a random wave field is determined and a corresponding distribution function of number of solitons on their amplitudes is constructed. The approach developed is illustrated by means of artificially generated quasi-random wave field and applied to the real data interpretation of wind waves generated in the laboratory wind tank.

scholarly journals MODIFICATION OF WAVE SPECTRA ON THE CONTINENTAL SHELF AND IN THE SURF ZONE

2011 ◽  
Vol 1 (8) ◽  
pp. 2 ◽  
Author(s):  
Charles L. Bretschneider
Keyword(s):  
Continental Shelf ◽  
Shallow Water ◽  
Surf Zone ◽  
Wind Waves ◽  
Wave Spectrum ◽  
Breaking Waves ◽  
Bottom Friction ◽  
Breaking Wave ◽  
Predominant Period ◽  
Significant Period

This paper discusses the problem pertaining to the modification of the wave spectrum over the continental shelf. Modification factors include bottom friction, percolation, refraction, breaking waves, ocean currents, and regeneration of wind waves in shallow water, among other factors. A formulation of the problem is presented but no general solution is made, primarily because of lack of basic data. Several special solutions are presented based on reasonable assumptions. The case for a steep continental shelf with parallel bottom contours and wave crests parallel to the coast and for which bottom friction is neglected has been investigated. For this case it is found that the predominant period shifts toward longer periods. The implication is, for example, that the significant periods observed along the U. S. Pacific coast are longer than those which would be observed several miles westward over deep water. The case for a gentle continental shelf with parallel bottom contour and wave crests parallel to the coast and for which bottom friction is important has also been investigated. For this case it is found that the predominant period shifts toward shorter periods as the water depth decreases. The implication is, for example, that the significant periods observed in the shallow water over the continental shelf are shorter than those which would be observed beyond the continental slope. In very shallow water, because shoaling becomes important, a secondary peak appears at higher periods. The joint distribution of wave heights and wave periods is required in order to determine the most probable maximum breaking wave, which can be of lesser height than the most probable maximum non-breaking wave. In very shallow water the most probable maximum breaking wave which first occurs would be governed by the breaking depth criteria, whereas in deepwater wave steepness can also be a governing factor. It can be expected that in very shallow water the period of the most probable maximum breaking wave should be longer than the significant period; and for deeper water the period of the most probable maximum breaking wave can be less than the significant period.

scholarly journals Ship mooring to jetties under the crosscurrent

Transport ◽  
2017 ◽  
Vol 33 (2) ◽  
pp. 454-460
Author(s):  
Vytautas Paulauskas ◽  
Donatas Paulauskas ◽  
Birutė Plačienė ◽  
Raimondas Barzdžiukas
Keyword(s):  
Shallow Water ◽  
Wind Waves ◽  
Water Effect ◽  
Shallow Water Effect ◽  
Theoretical Results

Quay walls or jetties in some ports or certain places of the ports are located in such a way that currents act at a particular angle to quay walls or jetties. Additional forces created by currents on mooring or moored ships as well as other forces produced by the wind, waves or shallow water effect should be taken in account when designing quay walls or jetties for ship mooring operations. The article describes ship mooring under crosscurrent conditions, calculates mooring methodology, experimentally examines the received theoretical results and provides recommendations to designers and ship operators when quay walls or jetties are arranged at a particular angle to the current.

Sign in / Sign up

Export Citation Format

Share Document