Non-Hydrostatic Model for Solitary Waves Passing Through a Porous Structure

2016 ◽  
Vol 11 (5) ◽  
pp. 957-963 ◽  
Author(s):  
Ikha Magdalena ◽  
◽  
Keyword(s):  
Porous Structure ◽  
Solitary Waves ◽  
Hydrodynamic Pressure ◽  
Flat Bottom ◽  
Boussinesq Model ◽  
Free Region ◽  
Hydrostatic Model ◽  
Pass Through ◽  
Predictor Corrector ◽  
Wave Transmission Coefficient

The non-hydrostatic depth-integrated model we developed to study solitary waves passing undisturbed in shape through a porous structure, involves hydrodynamic pressure. The equations are nonlinear, diffusive, and weakly dispersive wave equation for describing solitary wave propagation in a porous medium. We solve the equation numerically using a staggered finite volume with a predictor-corrector method. To demonstrate our non-hydrostatic scheme’s performance, we implement our scheme for simulating solitary waves over a flat bottom in a free region to examine the balance between dispersion and nonlinearity. Our computed waves travel undisturbed in shape as expected. Furthermore, the numerical scheme is used to simulate the solitary waves pass through a porous structure. Results agree well with results of a central finite difference method in space and a fourth-order Runge-Kutta integration technique in time for the Boussinesq model. When we quantitatively compare the wave amplitude reduction from our numerical results to experimental data, we find satisfactory agreement for the wave transmission coefficient.

scholarly journals An Efficient Two-Layer Non-Hydrostatic Model for Investigating Wave Run-Up Phenomena

Computation ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 1 ◽  
Author(s):  
Ikha Magdalena ◽  
Novry Erwina
Keyword(s):  
Solitary Waves ◽  
Hydrodynamic Pressure ◽  
Shape Preservation ◽  
Layer System ◽  
Flat Bottom ◽  
Hydrostatic Model ◽  
Run Up ◽  
Set Up ◽  
Volume Method ◽  
Sloping Beach

In this paper, we study the maximum run-up of solitary waves on a sloping beach and over a reef through a non-hydrostatic model. We do a modification on the non-hydrostatic model derived by Stelling and Zijlema. The model is approximated by resolving the vertical fluid depth into two-layer system. In contrast to the two-layer model proposed by Stelling, here, we have a block of a tridiagonal matrix for the hydrodynamic pressure. The equations are then solved by applying a staggered finite volume method with predictor-corrector step. For validation, several test cases are presented. The first test is simulating the propagation of solitary waves over a flat bottom. Good results in amplitude and shape preservation are obtained. Furthermore, run-up simulations are conducted for solitary waves climbing up a sloping beach, following the experimental set-up by Synolakis. In this case, two simulations are performed with solitary waves of small and large amplitude. Again, good agreements are obtained, especially for the prediction of run-up height. Moreover, we validate our numerical scheme for wave run-up simulation over a reef, and the result confirms the experimental data.

scholarly journals Head-on collision between capillary–gravity solitary waves

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Marin Marin ◽  
M. M. Bhatti
Keyword(s):  
Surface Tension ◽  
Solitary Waves ◽  
Water Waves ◽  
Free Parameter ◽  
Order Approximation ◽  
Third Order ◽  
Boussinesq Model ◽  
Run Up ◽  
Physical Features ◽  
Third Order Approximation

AbstractThe present study deals with the head-on collision process between capillary–gravity solitary waves in a finite channel. The present mathematical modeling is based on Nwogu’s Boussinesq model. This model is suitable for both shallow and deep water waves. We have considered the surface tension effects. To examine the asymptotic behavior, we employed the Poincaré–Lighthill–Kuo method. The resulting series solutions are given up to third-order approximation. The physical features are discussed for wave speed, head-on collision profile, maximum run-up, distortion profile, the velocity at the bottom, and phase shift profile, etc. A comparison is also given as a particular case in our study. According to the results, it is noticed that the free parameter and the surface tension tend to decline the solitary-wave profile significantly. However, the maximum run-up amplitude was affected in great measure due to the surface tension and the free parameter.

scholarly journals Numerical Modeling of the Interaction of Solitary Waves and Submerged Breakwaters with Sharp Vertical Edges Using One-Dimensional Beji & Nadaoka Extended Boussinesq Equations

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Mohammad H. Jabbari ◽  
Parviz Ghadimi ◽  
Ali Masoudi ◽  
Mohammad R. Baradaran
Keyword(s):  
Solitary Waves ◽  
Numerical Study ◽  
Time Integration ◽  
Boussinesq Equations ◽  
Linear Interpolation ◽  
Reflected Waves ◽  
One Dimensional ◽  
Propagating Waves ◽  
Linear Elements ◽  
Predictor Corrector

Using one-dimensional Beji & Nadaoka extended Boussinesq equation, a numerical study of solitary waves over submerged breakwaters has been conducted. Two different obstacles of rectangular as well as circular geometries over the seabed inside a channel have been considered in view of solitary waves passing by. Since these bars possess sharp vertical edges, they cannot directly be modeled by Boussinesq equations. Thus, sharply sloped lines over a short span have replaced the vertical sides, and the interactions of waves including reflection, transmission, and dispersion over the seabed with circular and rectangular shapes during the propagation have been investigated. In this numerical simulation, finite element scheme has been used for spatial discretization. Linear elements along with linear interpolation functions have been utilized for velocity components and the water surface elevation. For time integration, a fourth-order Adams-Bashforth-Moulton predictor-corrector method has been applied. Results indicate that neglecting the vertical edges and ignoring the vortex shedding would have minimal effect on the propagating waves and reflected waves with weak nonlinearity.

scholarly journals Generation of upstream advancing solitons by moving disturbances

1987 ◽  
Vol 184 ◽  
pp. 75-99 ◽  
Author(s):  
T. Yao-Tsu Wu
Keyword(s):  
Solitary Waves ◽  
Initial Boundary ◽  
Initial Boundary Value Problem ◽  
Theoretical Models ◽  
Computer Code ◽  
Basic Mechanism ◽  
Stationary Solutions ◽  
Boussinesq Model ◽  
Dispersive Waves ◽  
Fkdv Equation

This study investigates the recently identified phenomenon whereby a forcing disturbance moving steadily with a transcritical velocity in shallow water can generate, periodically, a succession of solitary waves, advancing upstream of the disturbance in procession, while a train of weakly nonlinear and weakly dispersive waves develops downstream of a region of depressed water surface trailing just behind the disturbance. This phenomenon was numerically discovered by Wu & Wu (1982) based on the generalized Boussinesq model for describing two-dimensional long waves generated by moving surface pressure or topography. In a joint theoretical and experimental study, Lee (1985) found a broad agreement between the experiment and two theoretical models, the generalized Boussinesq and the forced Korteweg-de Vries (fKdV) equations, both containing forcing functions. The fKdV model is applied in the present study to explore the basic mechanism underlying the phenomenon.To facilitate the analysis of the stability of solutions of the initial-boundary-value problem of the fKdV equation, a family of forced steady solitary waves is found. Any such solution, if once established, will remain permanent in form in accordance with the uniqueness theorem shown here. One of the simplest of the stationary solutions, which is a one-parameter family and can be scaled into a universal similarity form, is chosen for stability calculations. As a test of the computer code, the initially established stationary solution is found to be numerically permanent in form with fractional uncertainties of less than 2% after the wave has traversed, under forcing, the distance of 600 water depths. The other numerical results show that when the wave is initially so disturbed as to have to rise from the rest state, which is taken as the initial value, the same phenomenon of the generation of upstream-advancing solitons is found to appear, with a definite time period of generation. The result for this similarity family shows that the period of generation, Ts, and the scaled amplitude α of the solitons so generated are related by the formula Ts = const α−3/2. This relation is further found to be in good agreement with the first-principle prediction derived here based on mass, momentum and energy considerations of the fKdV equation.

scholarly journals An application of Nwogu’s Boussinesq model to analyze the head-on collision process between hydroelastic solitary waves

Open Physics ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 177-191 ◽  
Author(s):  
Muhammad Mubashir Bhatti ◽  
Dong-Qiang Lu
Keyword(s):  
Phase Shift ◽  
Solitary Waves ◽  
Free Parameter ◽  
Wave Speed ◽  
Physical Parameters ◽  
Beam Model ◽  
Boussinesq Model ◽  
Highly Nonlinear ◽  
Run Up ◽  
The Impact

AbstractThis article deals with the nonlinear head-on collision between two hydroelastic solitary waves in plate–covered water with Nwogou’s Boussinesq model for the nonlinear fluid motion. This model contains a parameter α that is associated with horizontal velocities according to the chosen level of horizontal velocity variables. A thin elastic cover is considered as the Euler–Bernoulli beam model. To derive the series solution, we apply the Poincaré–Lighthill–Kuo (PLK) method to solve analytically the highly nonlinear coupled partial differential equations. The impact of all the physical parameters is discussed with the help of the asymptotic solutions and graphic representations. In particular, the authors address the behavior of plate deflection, maximum run-up during a collision, phase shift, distortion profile, and wave speed. It is found that the variation of the free parameter α and plate terms dramatically change the amplitude of a solitary wave. It is noticed that a very small tilting occurs due to the distortion in wave profile. The maximum run-up amplitude and the wave speed rise due to a greater influence of the free parameter. The phase shift tends to diminish due to an increment in the free parameter and plate terms. The novelty of the present methodology is compared with previously published results.

Study on Solitary Waves of a General Boussinesq Model

2007 ◽  
Vol 48 (5) ◽  
pp. 773-780 ◽  
Author(s):  
Huang Shou-Jun ◽  
Chen Chun-Li
Keyword(s):  
Solitary Waves ◽  
Boussinesq Model

scholarly journals Run-Up of Solitary Waves on Twin Conical Islands Using a Boussinesq Model

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Dongfang Liang ◽  
Alistair G. L. Borthwick ◽  
Jonathan K. Romer-Lee
Keyword(s):  
Numerical Model ◽  
Solitary Waves ◽  
Laboratory Data ◽  
Boussinesq Model ◽  
Reflected Waves ◽  
Wave Refraction ◽  
Local Wave ◽  
Run Up ◽  
Gap Spacing ◽  
Incident Waves

This paper investigates the interaction of solitary waves (representative of tsunamis) with idealized flat-topped conical islands. The investigation is based on simulations produced by a numerical model that solves the two-dimensional Boussinesq-type equations of Madsen and Sørensen using a total variation diminishing Lax–Wendroff scheme. After verification against published laboratory data on solitary wave run-up at a single island, the numerical model is applied to study the maximum run-up at a pair of identical conical islands located at different spacings apart for various angles of wave attack. The predicted results indicate that the maximum run-up can be attenuated or enhanced according to the position of the second island because of wave refraction, diffraction, and reflection. It is also observed that the local wave height and hence run-up can be amplified at certain gap spacing between the islands, owing to the interference between the incident waves and the reflected waves between islands.

Propagation of solitary waves through significantly curved shallow water channels

1998 ◽  
Vol 362 ◽  
pp. 157-176 ◽  
Author(s):  
AIMIN SHI ◽  
MICHELLE H. TENG ◽  
THEODORE Y. WU
Keyword(s):  
Solitary Wave ◽  
Shallow Water ◽  
Solitary Waves ◽  
Wave Amplitude ◽  
Water Channels ◽  
Numerical Results ◽  
Channel Width ◽  
Boussinesq Model ◽  
Reflected Wave ◽  
Transmission And Reflection

Propagation of solitary waves in curved shallow water channels of constant depth and width is investigated by carrying out numerical simulations based on the generalized weakly nonlinear and weakly dispersive Boussinesq model. The objective is to investigate the effects of channel width and bending sharpness on the transmission and reflection of long waves propagating through significantly curved channels. Our numerical results show that, when travelling through narrow channel bends including both smooth and sharp-cornered 90°-bends, a solitary wave is transmitted almost completely with little reflection and scattering. For wide channel bends, we find that, if the bend is rounded and smooth, a solitary wave is still fully transmitted with little backward reflection, but the transmitted wave will no longer preserve the shape of the original solitary wave but will disintegrate into several smaller waves. For solitary waves travelling through wide sharp-cornered 90°-bends, wave reflection is seen to be very significant, and the wider the channel bend, the stronger the reflected wave amplitude. Our numerical results for waves in sharp-cornered 90°-bends revealed a similarity relationship which indicates that the ratios of the transmitted and reflected wave amplitude, excess mass and energy to the original wave amplitude, mass and energy all depend on one single dimensionless parameter, namely the ratio of the channel width b to the effective wavelength λe. Quantitative results for predicting wave transmission and reflection based on b/λe are presented.

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