scholarly journals A MODEL IN FREQUENCY DOMAIN FOR TRANSFORMATION OF FULLY DISPERSIVE NONLINEAR WAVES

2018 ◽  
pp. 60
Author(s):  
Samira Ardani ◽  
James M. Kaihatu
Keyword(s):  
Frequency Domain ◽  
Evolution Equations ◽  
Wave Model ◽  
Multiple Scale ◽  
Transformation Model ◽  
Wave Transformation ◽  
Numerical Verification ◽  
Resonant Interactions ◽  
Dispersive Model ◽  
Mathematical Derivation

In this study, mathematical derivation and numerical verification of a wave transformation model in frequency domain is discussed. This wave model is fully dispersive and nonlinear; and is derived based on the WKB assumptions. Transforming the problem into the frequency domain and using multiple scale analysis in space and perturbation theory, the model is expanded up to second order in wave steepness. This fully dispersive nonlinear wave model is a set of evolution equations which explicitly contains quadratic near-resonant interactions. The comparison between the presented model, the existing fully dispersive model and a nearshore model with different set of laboratory and field data shows that the presented model provides significant improvements particularly at higher frequencies.

SPECTRAL WAVE MODELLING IN TIDAL INLET SEAS: RESULTS FROM THE SBW WADDEN SEA PROJECT

2011 ◽  
Vol 1 (32) ◽  
pp. 44 ◽  
Author(s):  
Ap Van Dongeren ◽  
Andre Van der Westhuysen ◽  
Jacco Groeneweg ◽  
Gerbrant Van Vledder ◽  
Joost Lansen ◽  
...  
Keyword(s):  
Wave Height ◽  
Wave Breaking ◽  
Wadden Sea ◽  
Low Frequency ◽  
Wave Model ◽  
Finite Depth ◽  
Transformation Model ◽  
Wave Transformation ◽  
Sea Waves ◽  
Wave Conditions

Over the last five years a research program has been carried out to assess the performance of the spectral wave model SWAN in the Wadden Sea so that it may be used for the transformation of offshore wave conditions to wave boundary conditions near the sea defenses (dikes and dunes). The assessment was done on the basis of extensive wave measurements conducted in Ameland inlet and the Dutch Eastern Wadden Sea, as well as relevant data from lakes and estuaries. After a first round of assessment, we found that SWAN performed reasonably well for storm conditions but three aspects required further attention. Firstly, focusing on the main channel, SWAN formulations needed to be modified in order to eliminate overprediction of the significant wave height in opposing currents. Secondly, the primary spectral peak of North Sea waves penetrating into the inlet was underpredicted. Best results were obtained when the refraction of low-frequency waves was limited and the bottom friction coefficient was set at a lower value than the current default for wind seas. Thirdly, over the tidal flats the computed ratio of integral wave height over water depth showed an apparent upper limit using the conventional Battjes and Janssen (1978) depth-limited wave breaking formulation, because the wave growth over finite depth is hampered by the present formulation of depth-induced wave breaking. The problem has been solved using a new breaker formulation. All these improvements have lead to a wave transformation model with which reliable wave conditions in the Wadden Sea and related complex areas can be determined.

scholarly journals A LABORATORY AND FIELD STUDY ON 2DH SPECTRAL WAVE TRANSFORMATION IN MUDDY ENVIRONMENTS

2012 ◽  
Vol 1 (33) ◽  
pp. 39
Author(s):  
Mohsen Soltanpour ◽  
S. Abbas Haghshenas ◽  
Tomoya Shibayama
Keyword(s):  
Wave Spectrum ◽  
Field Measurements ◽  
Wave Model ◽  
Transformation Model ◽  
Wave Transformation ◽  
S Wave ◽  
North West ◽  
The North ◽  
Wave Basin ◽  
The Persian Gulf

The present paper offers a set of wave basin experiments on muddy beds together with field measurements data at Hendijan Mud Coast in the north-west corner of the Persian Gulf in order to investigate the 2DH spectral wave transformation over muddy beds. A dissipation model was added to REF/DIF S wave model to develop a numerical wave spectrum transformation model for muddy beaches. The proposed model was utilized to analyze the experimental and field measurements data on muddy beds. The simulated wave spectra over-mud bed are in fair agreement with the measurements.

Simulation of Water Wave Transformation Using Higher Order Mild-Slope Equation

2009 ◽  
Author(s):  
Tai-Wen Hsu ◽  
Ta-Yuan Lin ◽  
Kuan-Yu Hsiao ◽  
Shiao-Yin Chen
Keyword(s):  
Multiple Scale ◽  
Higher Order ◽  
Wave Transformation ◽  
Radiation Boundary Conditions ◽  
Depth Function ◽  
Mild Slope Equation ◽  
Scale Perturbation ◽  
Radiation Boundary ◽  
Wave Nonlinearity ◽  
Sloping Beach

A higher-order mild-slope equation (HOMSE) was developed using classical Galerkin method in which the depth function is expanded to the third-order. Wave nonlinearity and bottom slope parameters are involved in the depth function solved on the bases of the multiple-scale perturbation method. The equation is solved subject to the radiation boundary conditions by means of the procedure of parabolic formulation. Good agreement between numerical results and experimental data has been observed for wave propagation over a submerged obstacle and a sloping beach.

scholarly journals Far-Field Characteristics of Linear Water Waves Generated by a Submerged Landslide over a Flat Seabed

2020 ◽  
Vol 8 (3) ◽  
pp. 196
Author(s):  
Haixiao Jing ◽  
Yanyan Gao ◽  
Changgen Liu ◽  
Jingming Hou
Keyword(s):  
Shallow Water ◽  
Water Depth ◽  
Water Waves ◽  
Wave Model ◽  
Linear Wave ◽  
Far Field ◽  
Constant Depth ◽  
Low Froude Number ◽  
Dispersive Model ◽  
Wave Models

Understanding the propagation of landslide-generated water waves is of great help against tsunami hazards. In order to investigate the effects of landslide shapes on the far-field leading wave generated by a submerged landslide at a constant depth, three linear wave models with different degrees of dispersive properties are employed in this study. The linear fully dispersive model is then validated by comparing the results against the experimental data available for landslides with a low Froude number. Three simplified shapes of landslides with the same volume, which are unnatural for a body of incoherent material, are used to investigate the effects of landslide shapes on the far-field properties of the generated leading wave over a flat seabed. The results show that the far-field leading crest over a constant depth is independent of the exact landslide shape and is invalid at a shallow water depth. Therefore, the most popular non-dispersive model (also called the shallow water wave model) cannot be used to reproduce the phenomenon. The weakly dispersive wave model can predict this phenomenon well. If only the leading wave is considered, this model is accurate up to at least μ = h0/Lc = 0.6, where h0 is the water depth and Lc denotes the characteristic length of the landslide.

Numerical Verification of Thermal Stability Requirements for LISA Inertial Sensor in the Frequency Domain

2003 ◽  
Author(s):  
Marco Molina ◽  
Christian Vettore ◽  
Laura Beretta ◽  
Fabio Nappo ◽  
Federico Pamio ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Frequency Domain ◽  
Inertial Sensor ◽  
Numerical Verification
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