scholarly journals Numerical model for simulation of waves in surfzone and nearshore areas based on Boussinesq equations: results for plane beaches

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Phung Dang Hieu ◽  
Le Duc Dung ◽  
Nguyen Thi Khang
Keyword(s):  
Numerical Model ◽  
Wave Breaking ◽  
Boussinesq Equations ◽  
Rip Currents ◽  
Boussinesq Model ◽  
2D Boussinesq Equations ◽  
Volume Method ◽  
Sloping Beach ◽  
Wave Induced ◽  
Physical Phenomena

A numerical model based on the 2D Boussinesq equations has been developed using the Finite Volume Method. The model was verified against experimental data for the case of wave breaking on a sloping beach. Simulated results by the model showed that the model has good capability of simulation of waves in the nearshore area. Numerical simulation was also carried out for the problem of waves on a plane beach with a breakwater and submerged dunes. Simulated results were compared with those computed by MIKE 21. The comparison showed that good agreements were obtained and confirmed the applicability of the Boussinesq model to the simulation of physical phenomena of waves in the nearshore areas, especially, suitable for the simulation of wave-induced current including rip currents.

scholarly journals LONGSHORE CURRENTS IN ONE AND MULTI-BAR PROFILES RELATION TO LITTORAL DRIFT

2011 ◽  
Vol 1 (8) ◽  
pp. 15
Author(s):  
Per Bruun
Keyword(s):  
Wave Breaking ◽  
Breaking Waves ◽  
Current Theory ◽  
Current Approach ◽  
Rip Currents ◽  
Longshore Current ◽  
Littoral Drift ◽  
Longshore Currents ◽  
Average Water ◽  
Sloping Beach

This paper deals with longshore current theories. Introductorily it gives a brief review of wave theories for breaking waves including theoretical, laboratory as well as field results. Next the longshore current theory based on the momentum inflow over a uniformly sloping beach and bottom (Putnam, Munk and Traylor, 1949) is discussed with special reference to its friction factor. The following chapters deal with two new longshore current theories - both based on the continuity principle. One of them called the rip current approach assumes that all water thrown in by wave breaking runs out in rip currents and will probably be valid for profiles with well developed bars and waves approaching the shore almost perpendicularly. The other theory considers the fact that water from a wave breaking under an angle with the bar flows in with a certain phase difference in time longshore and this will create a longshore slope of the average water table, therefore also a longshore current. The water may return to sea uniformly as undertow or in rip currents or by a combination of both. This theory is particularly valid for waves breaking under a certain, not too small, angle with the bar. In both cases the momentum in the breaking waves is ignored because field observations show that in a well developed bar profile most of the momentum has disappeared inside the bar after wave breaking. Examples of computation of current velocities for one bar as well as multi-bar profiles are given. Next the possible relation between longshore currents and littoral drift is discussed.

Wave-induced forces on the giant kelp Macrocystis pyrifera (Agardh): field test of a computational model

1996 ◽  
Vol 199 (12) ◽  
pp. 2645-2654 ◽  
Author(s):  
B Utter ◽  
M Denny
Keyword(s):  
Numerical Model ◽  
Field Test ◽  
Wave Breaking ◽  
Mechanical Design ◽  
Ocean Waves ◽  
Macrocystis Pyrifera ◽  
Giant Kelp ◽  
Storm Waves ◽  
Maximal Tension ◽  
Wave Induced

We propose a hydro-mechanical numerical model that predicts the maximal tension to which stipes of the giant kelp Macrocystis pyrifera will be subjected when exposed to ocean waves. Predicted maximal tensions are close to those measured in the field. The strength of Macrocystis pyrifera stipes was measured, allowing our prediction of forces to be translated into a prediction of the fraction of stipes broken. Predicted breakage is low even for extreme storm waves, a testament to the mechanical design of individual kelp fronds. However, empirically measured rates of kelp mortality can be high, considerably higher than those predicted on the basis of hydrodynamic forces acting alone. This indicates that factors not taken into account in our model (such as holdfast dislodgment, entanglement of stipes, damage from herbivory and wave breaking) contribute substantially to mortality in Macrocystis pyrifera.

The mathematical modelling of corrosion in hot dip galvanized steel reinforced concrete

2011 ◽  
Vol 2 (1) ◽  
pp. 1-12
Author(s):  
A. Hegyi ◽  
H. Vermeşan ◽  
V. Rus
Keyword(s):  
Mathematical Model ◽  
Reinforced Concrete ◽  
Numerical Model ◽  
Equation System ◽  
Galvanized Steel ◽  
Steel Reinforced Concrete ◽  
Numeric Model ◽  
Physical And Mathematical Models ◽  
Physical Phenomena ◽  
The Mathematical Model

Abstract In this paper we wish to present the numerical model elaborated in order to simulate some physical phenomena that influence the general deterioration of steel, whether hot dip galvanized or not, in reinforced concrete. We describe the physical and mathematical models, establishing the corresponding equation system, the initial and boundary conditions. We have also presented the numeric model associated to the mathematical model and the numeric methods of discretization and solution of the differential equations system that describes the mathematical model.

Three-dimensional numerical simulation of wave-induced scour around a pile on a sloping beach

2021 ◽  
Vol 233 ◽  
pp. 109174
Author(s):  
Jinzhao Li ◽  
David R. Fuhrman ◽  
Xuan Kong ◽  
Mingxiao Xie ◽  
Yilin Yang
Keyword(s):  
Numerical Simulation ◽  
Three Dimensional ◽  
Sloping Beach ◽  
Wave Induced

scholarly journals Resonant Periods of Seiches in Semi-Closed Basins with Complex Bottom Topography

Fluids ◽  
2021 ◽  
Vol 6 (5) ◽  
pp. 181
Author(s):  
Ikha Magdalena ◽  
Nadhira Karima ◽  
Hany Qoshirotur Rif’atin
Keyword(s):  
Separation Of Variables ◽  
Bottom Topography ◽  
Small Error ◽  
Staggered Grid ◽  
Resonant Wave ◽  
Wave Elevation ◽  
External Forces ◽  
Volume Method ◽  
Resonant Period ◽  
Wave Induced

Seiches and resonances are two closely related phenomena that can cause damage to coastal areas. Seiches that occur in a basin at a distinct period named the resonant period may generate resonance when a wave induced by external forces enters the basin and has the same period as the seiches. Studying this period has become essential if we want to understand the resonance better. Thus, in this paper, we derive the resonant period in various shapes of semi-closed basin using the shallow water equations. The equations are then solved analytically using the separation of variables method and numerically using the finite volume method on staggered grid to discover the resonant period for each basin. To validate the numerical scheme, we compare its results against the analytical resonant periods, resulting in a very small error for each basin, suggesting that the numerical model is quite reliable in the estimation of the analytical resonant period. Further, resonant wave profiles are also observed. It is revealed that, in the coupled rectangular basin, the maximum wave elevation is disproportionate to the ratio of the length of the basin, while, in the trapezoidal basin, the ratio of the depth of the basin has no significant impact on the maximum wave elevation.

Experimental and Numerical Investigation Into the Effects of Initial Conditions on a Three Degree of Freedom Capsize Model

2006 ◽  
Vol 50 (01) ◽  
pp. 63-84
Author(s):  
Young-Woo Lee ◽  
Leigh McCue ◽  
Michael Obar ◽  
Armin Troesch
Keyword(s):  
Numerical Model ◽  
Numerical Investigation ◽  
Initial Conditions ◽  
Degree Of Freedom ◽  
Transient Effects ◽  
Ultimate State ◽  
Extreme Behavior ◽  
Three Degree Of Freedom ◽  
Physical Phenomena ◽  
Ship Capsizing

The dynamics and hydrodynamics of ship capsizing include strong nonlinearities, transient effects, and physical phenomena that have not been fully identified or studied. This paper presents a study of some of the various mechanisms associated with this extreme behavior. A quasi-nonlinear three degree of freedom numerical model is employed to examine the effects of initial conditions on the ultimate state of a box barge model. The numerical results are then used to provide structure and understanding to otherwise seemingly inconsistent and ambiguous experiments.

scholarly journals Numerical Simulation of Wave Propagation, Breaking, and Setup on Steep Fringing Reefs

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1147 ◽  
Author(s):  
Shanju Zhang ◽  
Liangsheng Zhu ◽  
Jianhua Li
Keyword(s):  
Finite Difference ◽  
Finite Volume ◽  
Boussinesq Equations ◽  
Transformation Process ◽  
Wave Transformation ◽  
Computational Accuracy ◽  
Irregular Wave ◽  
Eddy Viscosity Model ◽  
Fringing Reefs ◽  
Volume Method

The prediction of wave transformation and associated hydrodynamics is essential in the design and construction of reef top structures on fringing reefs. To simulate the transformation process with better accuracy and time efficiency, a shock-capturing numerical model based on the extended Boussinesq equations suitable for rapidly varying topography with respect to wave transformation, breaking and runup, is established. A hybrid finite volume–finite difference scheme is used to discretize conservation form of the extended Boussinesq equations. The finite-volume method with a HLL Riemann solver is applied to the flux terms, while finite-difference discretization is applied to the remaining terms. The fourth-order MUSCL (Monotone Upstream-centered Schemes for Conservation Laws) scheme is employed to create interface variables, with in which the van-Leer limiter is adopted to improve computational accuracy on complex topography. Taking advantage of van-Leer limiter, a nested model is used to take account of both computational run time and accuracy. A modified eddy viscosity model is applied to better accommodate wave breaking on steep reef slopes. The established model is validated with laboratory measurements of regular and irregular wave transformation and breaking on steep fringing reefs. Results show the model can provide satisfactory predictions of wave height, mean water level and the generation of higher harmonics.

scholarly journals On the asymptotic stability of stratified solutions for the 2D Boussinesq equations with a velocity damping term

2019 ◽  
Vol 29 (07) ◽  
pp. 1227-1277 ◽  
Author(s):  
Ángel Castro ◽  
Diego Córdoba ◽  
Daniel Lear
Keyword(s):  
Asymptotic Stability ◽  
Boussinesq Equations ◽  
Boussinesq Approximation ◽  
Damping Term ◽  
Temperature Variations ◽  
Strip Domain ◽  
2D Boussinesq Equations

We consider the 2D Boussinesq equations with a velocity damping term in a strip domain, with impermeable walls. In this physical scenario, where the Boussinesq approximation is accurate when density or temperature variations are small, our main result is the asymptotic stability for a specific type of perturbations of a stratified solution.

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