scholarly journals WAVE HEIGHT DISTRIBUTION OF WIND WAVES OVER LONG WAVES

1976 ◽  
Vol 1 (15) ◽  
pp. 21
Author(s):  
Shan-Hwei Ou ◽  
Frederick L.W. Tang
Keyword(s):  
Wave Height ◽  
Wave Energy ◽  
Wind Wave ◽  
Wind Waves ◽  
Rayleigh Distribution ◽  
Long Waves ◽  
Height Distribution ◽  
Long Wave ◽  
Wave Height Distribution ◽  
Wave Generator

Influence of long wave on the wave height distribution of wind waves was studied through the laboratory experiment. Experiments were conducted in a wind-wave tank where the wind waves were generated by a wind blower and the long waves were developed by an oscillating pendulum type wave generator. The wave height distribution of the wind waves over long wave is slightly different from the Rayleigh distribution in the small steepness of long wave. The ratios between the average of highest l/n-th waves vary with the steepness of long waves. The magnitude and the location of the spectral peak of wind waves are altered. The amount of the attenuation of wind wave energy is larger than the results of Mitsuyasu (1966).

Experimental study on the wave height distribution of wind-induced waves in the growth stage under finite water depth

2019 ◽  
Vol 19 (8) ◽  
pp. 2270-2279
Author(s):  
Ang Gao ◽  
Shiqiang Wu ◽  
Li Chen ◽  
Sien Liu ◽  
Zhun Xu ◽  
...  
Keyword(s):  
Wave Height ◽  
Water Depth ◽  
Growth Stage ◽  
Wind Wave ◽  
Model Parameters ◽  
Height Distribution ◽  
Distribution Models ◽  
Wave Height Distribution ◽  
Comparison Results ◽  
Optimized Model

Abstract With the method of a wind tank experiment, the real scenario of lakes with horizontal and vertical circulation of wind-induced flows is considered, and the features of wind wave height and its distribution in the different conditions of wind blowing distance, wind speed and water depth are studied systematically. Afterwards, comparison of the wave height distributions derived directly from experiment and the typical wave height distribution models show that some defects exist in typical wave height distribution models when describing wind wave height distribution in the wave growth stage. On this basis, we propose a new distribution model which is suitable for the description of wind wave height during the growth stage, and the model parameters are acquired with the programming solution method. Finally, the model is further optimized by relating B to σa, and Hs to σa. Comparison results of the optimized model and the typical ones show that the optimized model has advantages in calculation accuracy and convenience of use.

Dependence of Shape Parameter of Weibull Distribution on Wave Spectral Width and Nonlinearity

2008 ◽  
Author(s):  
Changliang Li ◽  
Bingchen Liang ◽  
Lin Zhao
Keyword(s):  
Weibull Distribution ◽  
Wave Height ◽  
Shape Parameter ◽  
Wave Train ◽  
Spectral Width ◽  
Rayleigh Distribution ◽  
Height Distribution ◽  
Irregular Wave ◽  
Wave Height Distribution ◽  
Ocean Environment

In practice, the wave height distribution associated with an irregular wave train is always mathematically modeled as a Rayleigh distribution. However, the realistic ocean wave height distribution might deviate from a Rayleigh distribution. The present study demonstrates that a better mathematical model for wave height distribution under realistic ocean environment is a Weibull distribution. In comparison with a Rayleigh distribution, a Weibull distribution has the flexibility on choosing its “shape parameter”. According to the nonlinear Monte Carlo simulations, this study investigates the nonlinearity and spectral width effects on the shape parameter for the Weibull wave height distribution. A new empirical formula for calculating the shape parameter is proposed, which can be used easily in application.

Influence of following, regular and irregular long waves on wind-wave growth with fetch: an experimental study

2021 ◽  
Author(s):  
Antoine Villefer ◽  
Michel Benoit ◽  
Damien Violeau ◽  
Christopher Luneau ◽  
Hubert Branger
Keyword(s):  
Wave Energy ◽  
Wind Wave ◽  
Wind Waves ◽  
Peak Frequency ◽  
Long Waves ◽  
Specific Method ◽  
Wave Growth ◽  
Wind Velocities ◽  
Series Of Experiments ◽  
Frequency Variations

AbstractA series of experiments were conducted in a wind-wave tank facility in Marseilles (France) to study the effects of preexisting swell conditions (represented by long mechanically-generated waves) on wind-wave growth with fetch. Both monochromatic and irregular (JONSWAP-type) long wave conditions with different values of wave steepness have been generated in the presence of a constant wind forcing, for several wind velocities. A spectral analysis of temporal wave signals combined with airflow measurements allowed to study the evolution of both wave systems with the aim of identifying the interaction mechanisms transportable to prototype scale. In particular, a specific method is used to separate the two wave systems in the measured bimodal spectra. In fetch-limited conditions, pure wind-wave growth is in accordance with anterior experiments, but differs from the prototype scale in terms of energy and frequency variations with fetch. Monochromatic long waves are shown to reduce the energy of the wind-waves significantly, as it was observed in anterior laboratory experiments. The addition of JONSWAP-type long waves instead results in a downshift of the wind-wave peak frequency but no significant energy reduction. Overall, it is observed that the presence of long waves affects the wind-wave energy and frequency variations with fetch. Finally, in the presence of JONSWAP-type long waves, variations of wind-wave energy and peak frequency with fetch appear in close agreement with the wind-wave growth observed at prototype scale both in terms of variations and nondimensional magnitude.

scholarly journals WAVE HEIGHT DISTRIBUTION IN CONSTANT AND FINITE DEPTHS

2012 ◽  
Vol 1 (33) ◽  
pp. 15 ◽  
Author(s):  
Sofia Caires ◽  
Marcel R.A. Van Gent
Keyword(s):  
Shallow Water ◽  
Wave Height ◽  
Wave Breaking ◽  
Rayleigh Distribution ◽  
Height Distribution ◽  
High Wave ◽  
Wave Height Distribution ◽  
Individual Wave ◽  
Wave Heights

Several alternatives to the Rayleigh distribution have been proposed for describing individual wave heights in regions where depth-induced wave breaking occurs. The most widely used of these is the so-called Battjes and Groenendijk distribution. This distribution has been derived and validated in a context of a shallow water foreshore waves propagating over a gently sloping shallow region towards the shore. Its validity for waves propagating in regions with shallow flat bottoms is investigated here. It is concluded that the distribution on average underestimates (outside its range of validity) high wave height measurements in shallow flat bottoms by as much as 15%.

scholarly journals PARAMETRIC REPRESENTATION OF A WIND-WAVE FIELD

1976 ◽  
Vol 1 (15) ◽  
pp. 11 ◽  
Author(s):  
Henrik Rye ◽  
Roald Svee
Keyword(s):  
Wave Field ◽  
Field Data ◽  
Wind Wave ◽  
Parametric Representation ◽  
Rayleigh Distribution ◽  
Spectral Shape ◽  
Height Distribution ◽  
Shape Parameters ◽  
Wave Parameters ◽  
Wave Height Distribution

The applicability of various spectral shape parameters is discussed. The wave .height distribution from 60 actual wave recordings is computed and compared to the Rayleigh distribution. The behaviour of various wave period parameters is discussed. Based on results from field data as well as numerical computations, it is concluded that some of the spectral wave parameters frequently used today may not be suitable for characterizing the wave field.

scholarly journals Loop-Type Wave-Generation Method for Generating Wind Waves under Long-Fetch Conditions

2017 ◽  
Vol 34 (10) ◽  
pp. 2129-2139 ◽  
Author(s):  
Naohisa Takagaki ◽  
Satoru Komori ◽  
Mizuki Ishida ◽  
Koji Iwano ◽  
Ryoichi Kurose ◽  
...  
Keyword(s):  
Wind Wave ◽  
Wind Waves ◽  
Peak Frequency ◽  
Wave Generation ◽  
New Wave ◽  
Wave Tank ◽  
Irregular Wave ◽  
Wind Speeds ◽  
Type Wave ◽  
Wave Generator

AbstractIt is important to develop a wave-generation method for extending the fetch in laboratory experiments, because previous laboratory studies were limited to the fetch shorter than several dozen meters. A new wave-generation method is proposed for generating wind waves under long-fetch conditions in a wind-wave tank, using a programmable irregular-wave generator. This new method is named a loop-type wave-generation method (LTWGM), because the waves with wave characteristics close to the wind waves measured at the end of the tank are reproduced at the entrance of the tank by the programmable irregular-wave generator and the mechanical wave generation is repeated at the entrance in order to increase the fetch. Water-level fluctuation is measured at both normal and extremely high wind speeds using resistance-type wave gauges. The results show that, at both wind speeds, LTWGM can produce wind waves with long fetches exceeding the length of the wind-wave tank. It is observed that the spectrum of wind waves with a long fetch reproduced by a wave generator is consistent with that of pure wind-driven waves without a wave generator. The fetch laws between the significant wave height and the peak frequency are also confirmed for the wind waves under long-fetch conditions. This implies that the ideal wind waves under long-fetch conditions can be reproduced using LTWGM with the programmable irregular-wave generator.

scholarly journals APPLICATIONS ON NONLINEAR WAVE COMBINATION

1986 ◽  
Vol 1 (20) ◽  
pp. 26
Author(s):  
J.T. Juang
Keyword(s):  
Wave Height ◽  
Taiwan Strait ◽  
Western Coast ◽  
Linear Wave ◽  
Wave System ◽  
Height Distribution ◽  
Wave Height Distribution ◽  
Local Wave ◽  
Source Wave ◽  
The Waves

Due to the special bathymetry in Taiwan Strait, the waves off the western coast of Taiwan are considered to be composed of two-source wave system. One propagates from the central part of the Strait named main wave, and the other is generated by the local wind known as local wave which occurs along the shore. After the combination and the transformation procedure from these two-nonlinear-source wave system, the wave height distribution in Taiwan Strait should be modified. A comparison of the wave height distributions based on the present proposed method with the field data indicates that the present method yields a better result than other theorems. Furthermore, the result of application of two non-linear wave theorem to wave prediction are also presented.

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