Numerical modeling for breaking wave-induced momentary liquefaction in a porous seabed

2004 ◽  
pp. 339-345
Author(s):  
H Zhang ◽  
D Jeng
Keyword(s):  
Numerical Modeling ◽  
Breaking Wave ◽  
Wave Induced

scholarly journals Numerical modeling of breaking wave induced seawall scour

2019 ◽  
Vol 150 ◽  
pp. 108-120 ◽  
Author(s):  
Nadeem Ahmad ◽  
Hans Bihs ◽  
Dag Myrhaug ◽  
Arun Kamath ◽  
Øivind A. Arntsen
Keyword(s):  
Numerical Modeling ◽  
Breaking Wave ◽  
Wave Induced

Topographically controlled, breaking-wave-induced macrovortices. Part 1. Widely separated breakwaters

2004 ◽  
Vol 507 ◽  
pp. 289-307 ◽  
Author(s):  
M. BROCCHINI ◽  
A. KENNEDY ◽  
L. SOLDINI ◽  
A. MANCINELLI
Keyword(s):  
Breaking Wave ◽  
Wave Induced

Topographically controlled, breaking-wave-induced macrovortices. Part 2. Changing geometries

2006 ◽  
Vol 559 ◽  
pp. 57 ◽  
Author(s):  
A. B. KENNEDY ◽  
M. BROCCHINI ◽  
L. SOLDINI ◽  
E. GUTIERREZ
Keyword(s):  
Breaking Wave ◽  
Wave Induced

scholarly journals 3D Modeling and Mechanism Analysis of Breaking Wave-Induced Seabed Scour around Monopile

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Xiaojian Liu ◽  
Cheng Liu ◽  
Xiaowei Zhu ◽  
Yong He ◽  
Qisong Wang ◽  
...  
Keyword(s):  
Shear Stress ◽  
Sediment Transport ◽  
Stokes Equations ◽  
Volume Fraction ◽  
Laboratory Data ◽  
Suspended Load ◽  
Breaking Wave ◽  
Offshore Structure ◽  
Nearshore Sediment Transport ◽  
Wave Induced

Breaking wave-induced scour is recognized as one of the major causes of coastal erosion and offshore structure failure, which involves in the full 3D water-air-sand interaction, raising a great challenge for the numerical simulation. To better understand this process, a nonlinear 3D numerical model based on the open-source CFD platform OpenFOAM® was self-developed in this study. The Navier–Stokes equations were used to compute the two-phase incompressible flow, combining with the finite volume method (FVM) to discretize calculation domain, a modified VOF method to track the free surface, and a k−ε model to closure the turbulence. The nearshore sediment transport process is reproduced in view of shear stress, suspended load, and bed load, in which the terms of shear stress and suspended load were updated by introducing volume fraction. The seabed morphology is updated based on Exner equation and implemented by dynamic mesh technique. The mass conservative sand slide algorithm was employed to avoid the incredible vary of the bed mesh. Importantly, a two-way coupling method connecting the hydrodynamic module with the beach morphodynamic module is implemented at each computation step to ensure the fluid-sediment interaction. The capabilities of this model were calibrated by laboratory data from some published references, and the advantages/disadvantages, as well as proper recommendations, were introduced. Finally, nonbreaking- and breaking wave-induced scour around the monopile, as well as breaking wave-induced beach evolution, were reproduced and discussed. This study would be significantly helpful to understand and evaluate the nearshore sediment transport.

scholarly journals Study of Current- and Wave-Induced Sediment Transport in the Nowshahr Port Entrance Channel by Using Numerical Modeling and Field Measurements

2020 ◽  
Vol 8 (4) ◽  
pp. 284 ◽  
Author(s):  
Ayyuob Mahmoodi ◽  
Mir Ahmad Lashteh Neshaei ◽  
Abbas Mansouri ◽  
Mahmood Shafai Bejestan
Keyword(s):  
Numerical Modeling ◽  
Caspian Sea ◽  
Recirculation Zone ◽  
Numerical Models ◽  
Field Measurements ◽  
Sediment Sources ◽  
The Caspian Sea ◽  
Access Channel ◽  
Negative Impacts ◽  
Wave Induced

The Nowshahr port in the southern coastlines of the Caspian Sea is among the oldest northern ports of Iran, first commissioned in the year 1939. In recent years, this port has been faced with severe sedimentation issues in and around its entrance that has had negative impacts on the operability of the port. The present study aims at identifying major reasons for severe sedimentation in the port entrance. First, field measurements were evaluated to gain an in-depth view of the hydrodynamics of the study area. Numerical models then were calibrated and validated against existing field measurements. Results of numerical modeling indicated that wind-induced current is dominant in the Caspian Sea. The numerical results also indicated that in the case of an eastward current direction, the interaction between current and the western breakwater arm would lead to the formation of a separation zone and a recirculation zone to the east of the port entrance region. This eddying circulation could transport suspend settled sediments from eastern shoreline towards the port entrance and its access channel. The results of this paper are mostly based on the study of current patterns around the port in the storm conditions incorporate with the identification of sediment sources.

Numerical modeling and laboratory measurements of seismic attenuation in partially saturated rock

Geophysics ◽  
2014 ◽  
Vol 79 (2) ◽  
pp. L13-L20 ◽  
Author(s):  
Maria Kuteynikova ◽  
Nicola Tisato ◽  
Ralf Jänicke ◽  
Beatriz Quintal
Keyword(s):  
Numerical Modeling ◽  
Seismic Attenuation ◽  
Laboratory Measurements ◽  
Berea Sandstone ◽  
Mesoscopic Scale ◽  
Partially Saturated ◽  
Saturated Rock ◽  
Fluid Saturation ◽  
The Matrix ◽  
Wave Induced

To better understand the effects of fluid saturation on seismic attenuation, we combined numerical modeling in poroelastic media and laboratory measurements of seismic attenuation in partially saturated Berea sandstone samples. Although in laboratory experiments many physical mechanisms for seismic attenuation take place simultaneously, with numerical modeling we separately studied the effect of a single physical mechanism: wave-induced fluid flow on the mesoscopic scale. Using the finite-element method, we solved Biot’s equations of consolidation by performing a quasistatic creep test on a 3D poroelastic model. This model represents a partially saturated rock sample. We obtained the stress-strain relation, from which we calculated frequency-dependent attenuation. In the laboratory, we measured attenuation in extensional mode for dry and partially water-saturated Berea sandstone samples in the frequency range from 0.1 to 100 Hz. All the measurements were performed at room pressure and temperature conditions. From numerical simulations, we found that attenuation varies significantly with fluid distribution within the model. In addition to binary distributions, we used spatially continuous distributions of fluid saturation for the numerical models. Such continuous saturation distribution was implemented using properties of an effective single-phase fluid. By taking into account the matrix anelasticity, we found that wave-induced fluid flow on the mesoscopic scale due to a continuous distribution of fluid saturation can reproduce seismic attenuation data measured in a partially saturated sample. The matrix anelasticity was the attenuation measured in the room-condition dry sample.

A Coupled VOF-Eulerian Multiphase CFD Model to Simulate Breaking Wave Impacts on Offshore Structures

2016 ◽  
Author(s):  
Pietro D. Tomaselli ◽  
Erik Damgaard Christensen
Keyword(s):  
Wave Breaking ◽  
Bubble Column ◽  
Vertical Cylinder ◽  
Air Entrainment ◽  
Offshore Structures ◽  
Laboratory Scale ◽  
Breaking Wave ◽  
Cfd Model ◽  
Bubble Plume ◽  
Wave Induced

Breaking wave-induced loads on offshore structures can be extremely severe. The air entrainment mechanism during the breaking process plays a not well-known role in the exerted forces. This paper present a CFD solver, developed in the Open-FOAM environment, capable of simulating the wave breaking-induced air entrainment. Firstly the model was validated against a bubble column flow. Then it was employed to compute the inline force exerted by a spilling breaking wave on a vertical cylinder in a 3D domain at a laboratory scale. Results showed that the entrained bubbles affected the magnitude of the force partially. Further analyses on the interaction of the bubble plume with the flow around the cylinder are needed.

scholarly journals One-dimensional modelling of upper ocean mixing by turbulence due to wave orbital motion

2014 ◽  
Vol 21 (1) ◽  
pp. 325-338 ◽  
Author(s):  
M. Ghantous ◽  
A. V. Babanin
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Sea Surface ◽  
Upper Ocean ◽  
Breaking Wave ◽  
Ocean Mixing ◽  
One Dimensional ◽  
Modelling Experiment ◽  
Wave Induced ◽  
Upper Ocean Mixing

Abstract. Mixing of the upper ocean affects the sea surface temperature by bringing deeper, colder water to the surface. Because even small changes in the surface temperature can have a large impact on weather and climate, accurately determining the rate of mixing is of central importance for forecasting. Although there are several mixing mechanisms, one that has until recently been overlooked is the effect of turbulence generated by non-breaking, wind-generated surface waves. Lately there has been a lot of interest in introducing this mechanism into ocean mixing models, and real gains have been made in terms of increased fidelity to observational data. However, our knowledge of the mechanism is still incomplete. We indicate areas where we believe the existing parameterisations need refinement and propose an alternative one. We use two of the parameterisations to demonstrate the effect on the mixed layer of wave-induced turbulence by applying them to a one-dimensional mixing model and a stable temperature profile. Our modelling experiment suggests a strong effect on sea surface temperature due to non-breaking wave-induced turbulent mixing.

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