scholarly journals On the influence of wind on extreme wave events

2007 ◽  
Vol 7 (1) ◽  
pp. 123-128 ◽  
Author(s):  
J. Touboul
Keyword(s):  
Numerical Analysis ◽  
Spectral Method ◽  
Modulational Instability ◽  
Rogue Waves ◽  
High Order ◽  
Instability Wave ◽  
Extreme Wave ◽  
Wave Fields ◽  
The Impact ◽  
High Order Spectral Method

Abstract. This work studies the impact of wind on extreme wave events, by means of numerical analysis. A High Order Spectral Method (HOSM) is used to generate freak, or rogue waves, on the basis of modulational instability. Wave fields considered here are chosen to be unstable to two kinds of perturbations. The evolution of components during the propagation of the wave fields is presented. Their evolution under the action of wind, modeled through Jeffreys' sheltering mechanism, is investigated and compared to the results without wind. It is found that wind sustains rogue waves. The perturbation most influenced by wind is not necessarily the most unstable.

Extreme wave statistics of random waves propagating over a 3D varying bathymetry

2021 ◽  
Author(s):  
Christopher Lawrence ◽  
Karsten Trulsen ◽  
Odin Gramstad
Keyword(s):  
Velocity Field ◽  
Spectral Method ◽  
Local Maximum ◽  
High Order ◽  
Surface Elevation ◽  
Irregular Waves ◽  
Extreme Wave ◽  
Boussinesq Model ◽  
Wave Statistics ◽  
High Order Spectral Method

<p>Non-uniform bathymetry may modify the wave statistics for both surface elevation and velocity field.<br>Laboratory evidence reported by Trulsen et al. (2012) shows that for a relatively long unidirectional<br>waves propagating over a sloping bottom, from deep to shallower water, there can be a local maximum<br>of kurtosis and skewness in surface elevation near the edge of the shallower side of the slope. Recent<br>laboratory experiments of long-crested irregular waves propagating over a shoal by Trulsen et al. (2020)<br>reported that the kurtosis of horizontal velocity field have different behaviour from the kurtosis of surface<br>elevation where the local maximum of kurtosis in surface elevation and horizontal velocity occur at<br>different location.<br>In present work, we utilize numerical simulation to study the evolution of skewness and kurtosis for<br>irregular waves propagating over a three-dimensional varying bathymetry. Numerical simulations are<br>based on High Order Spectral Method (HOSM) for variable depth as described in Gouin et al. (2017)<br>for wave evolution and Variational Boussinesq model (VBM) as described in Lawrence et al. (2021) for<br>velocity field calculation.</p><p> </p><p>References</p><p>GOUIN, M., DUCROZET, G. & FERRANT, P. 2017 Propagation of 3D nonlinear waves over an elliptical<br>mound with a High-Order Spectral method. Eur. J. Mech. B Fluids 63, 9–24.<br>LAWRENCE, C., GRAMSTAD, O. & TRULSEN, K. 2021 Variational Boussinesq model for kinematics<br>calculation of surface gravity waves over bathymetry. Wave Motion 100, 102665.<br>TRULSEN, K., RAUSTØL, A., JORDE, S. & RYE, L. 2020 Extreme wave statistics of long-crested<br>irregular waves over a shoal. J. Fluid Mech. 882, R2.<br>TRULSEN, K., ZENG, H. & GRAMSTAD, O. 2012 Laboratory evidence of freak waves provoked by<br>non-uniform bathymetry. Phys. Fluids 24, 097101.</p>

Predicting the occurrence of rogue waves in the presence of opposing currents with a high-order spectral method

2021 ◽  
Vol 6 (6) ◽  
Author(s):  
Guillaume Ducrozet ◽  
Maryam Abdolahpour ◽  
Filippo Nelli ◽  
Alessandro Toffoli
Keyword(s):  
Spectral Method ◽  
Rogue Waves ◽  
High Order ◽  
High Order Spectral Method

scholarly journals HOS-ocean: Open-source solver for nonlinear waves in open ocean based on High-Order Spectral method

2016 ◽  
Vol 203 ◽  
pp. 245-254 ◽  
Author(s):  
Guillaume Ducrozet ◽  
Félicien Bonnefoy ◽  
David Le Touzé ◽  
Pierre Ferrant
Keyword(s):  
Open Source ◽  
Spectral Method ◽  
Nonlinear Waves ◽  
Open Ocean ◽  
High Order ◽  
High Order Spectral Method

Re-study on recurrence period of Stokes wave train with high order spectral method

2011 ◽  
Vol 25 (4) ◽  
pp. 679-686 ◽  
Author(s):  
Ai-feng Tao ◽  
Jin-hai Zheng ◽  
Mee Soe Mee ◽  
Bo-tao Chen
Keyword(s):  
Spectral Method ◽  
Wave Train ◽  
High Order ◽  
Stokes Wave ◽  
Recurrence Period ◽  
High Order Spectral Method

On Signatures and Features of Modulational Instability in Ocean Waves

2019 ◽  
Author(s):  
Alexander V. Babanin
Keyword(s):  
Water Waves ◽  
Modulational Instability ◽  
Ocean Waves ◽  
Rogue Waves ◽  
Spectral Energy ◽  
Nonlinear Superposition ◽  
Relative Significance ◽  
Wave Fields ◽  
Ice Breakup ◽  
Surface Water Waves

Abstract Modulational instability of nonlinear waves in dispersive environments is known across a broad range of physical media, from nonlinear optics to waves in plasmas. Since it was discovered for the surface water waves in the early 60s, it was found responsible for, or able to contribute to the topics of breaking and rogue waves, swell, ice breakup, wave-current interactions and perhaps even spray production. Since the early days, however, the argument continues on whether the modulational instability, which is essentially a one-dimensional phenomenon, is active in directional wave fields (that is whether the realistic directional spectra are narrow enough to maintain such nonlinear behaviours). Here we discuss the distinct features of the evolution of nonlinear surface gravity waves, which should be attributed as signatures to this instability in oceanic wind-generated wave fields. These include: wave-breaking threshold in terms of average steepness; upshifting of the spectral energy prior to breaking; oscillations of wave asymmetry and skewness; energy loss from the carrier waves in the course of the breaking. We will also refer to the linear/nonlinear superposition of waves which is often considered a counterpart (or competing) mechanism responsible for breaking or rogue waves in the ocean. We argue that both mechanisms are physically possible and the question of in situ abnormal waves is a problem of their relative significance in specific circumstances.

Systematic Experimental Validation of High-Order Spectral Method for Deterministic Wave Prediction

2019 ◽  
Author(s):  
Marco Klein ◽  
Matthias Dudek ◽  
Günther F. Clauss ◽  
Norbert Hoffmann ◽  
Jasper Behrendt ◽  
...  
Keyword(s):  
Spectral Method ◽  
Experimental Validation ◽  
Linear Method ◽  
Wave Spectrum ◽  
High Order ◽  
Linear Wave ◽  
Short Term ◽  
Wave Prediction ◽  
Non Linear ◽  
High Order Spectral Method

Abstract The applicability of the High-Order Spectral Method (HOSM) as a very fast non-linear method for deterministic short-term wave prediction is discussed within this paper. The focus lies on the systematic experimental validation of the HOSM in order to identify and evaluate possible areas of application as well as limitations of use. For this purpose, irregular sea states with varying parameters such as wave steepness and underlying wave spectrum are addressed by numerical simulations and model tests in the controlled environment of a seakeeping basin. In addition, the influence of the propagation distance is discussed. For the evaluation of the accuracy of the HOSM prediction, the surface similarity parameter (SSP) is utilized, allowing a quantitative validation of the results. The results obtained are compared to linear wave prediction to discuss the pros and cons of a non-linear deterministic short-term wave prediction. In conclusion, this paper shows that the non-linear deterministic wave prediction based on HOSM leads to a substantial improvement of the prediction quality for moderate and steep irregular wave trains in terms of individual waves and prediction distance.

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