A numerical study of tsunami wave run-up and impact on coastal cliffs using a CIP-based model

Abstract. There is a general lack of the understanding of tsunami wave interacting with complex geographies, especially the process of inundation. Numerical simulations are performed to understand the effects of several factors on tsunami wave impact and run-up in the presence of submarine gentle slopes and coastal cliffs, using an in-house code, named a Constrained Interpolation Profile (CIP)-based model in Zhejiang University (CIP-ZJU). The model employs a high-order finite difference method, the CIP method as the flow solver, utilizes a VOF-type method, the Tangent of hyperbola for interface capturing/Slope weighting (THINC/SW) scheme to capture the free surface, and treats the solid boundary by an immersed boundary method. A series of incident waves are arranged to interact with varying coastal geographies. Numerical results are compared with experimental data and good agreement is obtained. The influences of submarine gentle slope, coastal cliff and incident wave height are discussed. It is found that the rule of tsunami amplification factor varying with incident wave is affected by angle of cliff slope, and there is a critical angle about 45°. The run-up on a toe-erosion cliff is smaller than that on a normal cliff. The run-up is also related to the length of submarine gentle slope with a critical about 2.292 m in the present study. The impact pressure on the cliff is extremely large and concentrated, and the backflow effect is nonnegligible. Results of our work are in high precision and helpful in inversing tsunami source and forecasting disaster.

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A numerical study of tsunami wave impact and run-up on coastal cliffs using a CIP-based model

Natural Hazards and Earth System Science ◽

10.5194/nhess-17-641-2017 ◽

2017 ◽

Vol 17 (5) ◽

pp. 641-655 ◽

Cited By ~ 2

Author(s):

Xizeng Zhao ◽

Yong Chen ◽

Zhenhua Huang ◽

Zijun Hu ◽

Yangyang Gao

Keyword(s):

Incident Wave ◽

Tsunami Wave ◽

Critical Value ◽

Tsunami Source ◽

Solid Boundary ◽

Wave Impact ◽

Submarine Slope ◽

Coastal Cliffs ◽

Run Up ◽

The Impact

Abstract. There is a general lack of understanding of tsunami wave interaction with complex geographies, especially the process of inundation. Numerical simulations are performed to understand the effects of several factors on tsunami wave impact and run-up in the presence of gentle submarine slopes and coastal cliffs, using an in-house code, a constrained interpolation profile (CIP)-based model. The model employs a high-order finite difference method, the CIP method, as the flow solver; utilizes a VOF-type method, the tangent of hyperbola for interface capturing/slope weighting (THINC/SW) scheme, to capture the free surface; and treats the solid boundary by an immersed boundary method. A series of incident waves are arranged to interact with varying coastal geographies. Numerical results are compared with experimental data and good agreement is obtained. The influences of gentle submarine slope, coastal cliff and incident wave height are discussed. It is found that the tsunami amplification factor varying with incident wave is affected by gradient of cliff slope, and the critical value is about 45°. The run-up on a toe-erosion cliff is smaller than that on a normal cliff. The run-up is also related to the length of a gentle submarine slope with a critical value of about 2.292 m in the present model for most cases. The impact pressure on the cliff is extremely large and concentrated, and the backflow effect is non-negligible. Results of our work are highly precise and helpful in inverting tsunami source and forecasting disaster.

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Spectral Analysis of Irregular Wave Impact on the Structure in Splash Zone

21st International Conference on Offshore Mechanics and Arctic Engineering, Volume 1 ◽

10.1115/omae2002-28091 ◽

2002 ◽

Cited By ~ 1

Author(s):

Bing Ren ◽

Yongxue Wang

Keyword(s):

Spectral Analysis ◽

Wave Height ◽

Incident Wave ◽

Impact Pressure ◽

Splash Zone ◽

Spectral Moment ◽

Wave Impact ◽

Large Wave ◽

Irregular Wave ◽

The Impact

The spectral analysis from experimental data of irregular wave impact on the structures with large dimension in the splash zone is presented. The experiments were conducted in the large wave-current tank in the State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology. In the experiment, the target spectrum is JONSWAP spectrum, the significant wave height H1/3 is in the range from 0.1m to 0.3m, and the peak period of spectrum Tp in the range from 1.0s to 2.0s. The ratio of s/H1/3, which refers to the clearance of the subface of the structure above still water level (s) to the incident wave height, is between −0.1 and 0.4. The spectral analysis results of the irregular wave impact pressure on the subface of the structure under various case studies are presented. The distribution of spectral moment of the impact pressure on the structure along the subface is given. And the influence of different incident wave parameters and relative clearance s/H1/3 on the average spectral moment of impact pressure are discussed.

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Numerical Study of the Wave Impact on a Square Column Using Large Eddy Simulation

Volume 3: Pipeline and Riser Technology; CFD and VIV ◽

10.1115/omae2007-29729 ◽

2007 ◽

Author(s):

H. T. C. Pedro ◽

K.-W. Leung ◽

M. H. Kobayashi ◽

H. R. Riggs

Keyword(s):

Numerical Study ◽

Turbulence Models ◽

Simple Algorithm ◽

Navier Stokes ◽

Wave Impact ◽

Eddy Simulation ◽

Subgrid Model ◽

Large Eddy ◽

Volume Approximation ◽

The Impact

This work concerns the numerical investigation of the impact of a wave on a square column. The wave is generated by a dam break in a wave tank. Two turbulence models were used: Large Eddy Simulations (LES) and Unsteady Reynolds Averaged Navier-Stokes (URANS). The numerical simulations were carried out using a finite volume approximation and the SIMPLE algorithm for the solution of the governing equations. Turbulence was modeled with the standard Smagorinsky-Lilly subgrid-model for the LES and the standard κ-ε model for the URANS. The results are validated against experimental data for the wave impact on a square column facing the flow. The results, especially for LES, show very good agreement between the predictions and experimental results. The overall accuracy of the LES, as expected, is superior to the URANS. However, if computational resources are limited, URANS can still provide satisfactory results for structural design.

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Numerical Study of Phase Change Influence on Wave Impact Loads in LNG Tanks on Floating Structures

Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics ◽

10.1115/omae2018-78643 ◽

2018 ◽

Cited By ~ 1

Author(s):

Matthieu Ancellin ◽

Laurent Brosset ◽

Jean-Michel Ghidaglia

Keyword(s):

Natural Gas ◽

Phase Change ◽

Numerical Study ◽

Model Tests ◽

Impact Loads ◽

Wave Impact ◽

Floating Structures ◽

Physical Phenomena ◽

The Impact ◽

Phase Phase

Understanding the physics of sloshing wave impacts is necessary for the improvement of sloshing assessment methodology based on sloshing model tests, for LNG membrane tanks on floating structures. The phase change between natural gas and liquefied natural gas is one of the physical phenomena involved during a LNG wave impact but is not taken into account during sloshing model tests. In this paper, some recent numerical and analytical works on the influence of phase change are summarized and discussed. For the impact of an ideally shaped wave, phase change influences two different steps of the impact in different ways: during the gas escape phase, phase change leads to a higher impact velocity; for entrapped gas pockets, phase change causes a reduction of the pressure in the gas pocket. However, this influence is quantitatively small. The generalization to more realistic wave shapes (including e.g. liquid aeration) should be the focus of future works.

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Numerical Study of Air Gap Response and Wave Impact Load on a Moored Semi-Submersible Platform in Predetermined Irregular Wave Train

29th International Conference on Ocean, Offshore and Arctic Engineering: Volume 6 ◽

10.1115/omae2010-20260 ◽

2010 ◽

Author(s):

Xiufeng Liang ◽

Jianmin Yang ◽

Longfei Xiao ◽

Xin Li ◽

Jun Li

Keyword(s):

Impact Load ◽

Numerical Study ◽

Wave Train ◽

Air Gap ◽

Navier Stokes ◽

Design Stage ◽

Wave Impact ◽

Irregular Wave ◽

Run Up ◽

Steep Waves

The importance of understanding air gap response and potential deck impact is well-known in the design stage of semi-submersible platform. The highly non-linear nature of wave elevation around large structures in steep waves makes it difficult to accurately predict wave field under the deck and wave run up along the columns. Present engineering tools for the prediction of air gap response generally based on simplified models. Even the models accounting for nonlinear wave diffraction is not free of uncertainties. A method adopted here couples a Navier-Stokes solver, VOF technique capturing violent free surface and DNV/Seasam predicting motions of moored semi-submersible platform. Air gap response at different locations of the hull was evaluated in predetermined irregular wave train. Wave run up was also measured by wave probes near the columns. Load cells were mounted under the deck of the platform to trace potential deck impact. The predetermined irregular wave train was simulated in a numerical wave tank and verified against physical tank results. Analysis of the air gap response, wave run up and impact loads on the semi-submersible platform were conducted.

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Impact of a 1755-like tsunami in Huelva, Spain

Natural Hazards and Earth System Science ◽

10.5194/nhess-10-139-2010 ◽

2010 ◽

Vol 10 (1) ◽

pp. 139-148 ◽

Cited By ~ 26

Author(s):

V. V. Lima ◽

J. M. Miranda ◽

M. A. Baptista ◽

J. Catalão ◽

M. Gonzalez ◽

...

Keyword(s):

Source Parameters ◽

Critical Factor ◽

Maximum Flow ◽

High Energy ◽

Tsunami Source ◽

Flow Depth ◽

Large Area ◽

Inundation Extent ◽

Run Up ◽

The Impact

Abstract. Coastal areas are highly exposed to natural hazards associated with the sea. In all cases where there is historical evidence for devastating tsunamis, as is the case of the southern coasts of the Iberian Peninsula, there is a need for quantitative hazard tsunami assessment to support spatial planning. Also, local authorities must be able to act towards the population protection in a preemptive way, to inform "what to do" and "where to go" and in an alarm, to make people aware of the incoming danger. With this in mind, we investigated the inundation extent, run-up and water depths, of a 1755-like event on the region of Huelva, located on the Spanish southwestern coast, one of the regions that was affected in the past by several high energy events, as proved by historical documents and sedimentological data. Modelling was made with a slightly modified version of the COMCOT (Cornell Multi-grid Coupled Tsunami Model) code. Sensitivity tests were performed for a single source in order to understand the relevance and influence of the source parameters in the inundation extent and the fundamental impact parameters. We show that a 1755-like event will have a dramatic impact in a large area close to Huelva inundating an area between 82 and 92 km2 and reaching maximum run-up around 5 m. In this sense our results show that small variations on the characteristics of the tsunami source are not too significant for the impact assessment. We show that the maximum flow depth and the maximum run-up increase with the average slip on the source, while the strike of the fault is not a critical factor as Huelva is significantly far away from the potential sources identified up to now. We also show that the maximum flow depth within the inundated area is very dependent on the tidal level, while maximum run-up is less affected, as a consequence of the complex morphology of the area.

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ANALYSIS OF THE IMPACT PROCESS AT DIKES WITH CROWN WALLS AND PARAPETS

Coastal Engineering Proceedings ◽

10.9753/icce.v36v.papers.55 ◽

2020 ◽

pp. 55

Author(s):

Giuseppina Palma ◽

Sara Mizar Formentin ◽

Barbara Zanuttigh

Keyword(s):

Image Analysis ◽

Breaking Waves ◽

Small Scale ◽

Wave Forces ◽

Hydraulic Parameters ◽

Wave Impact ◽

Impact Process ◽

Air Content ◽

Run Up ◽

The Impact

This paper is focused on the analysis of the impact process at dikes with crown walls and parapets under breaking and non-breaking waves. A small-scale laboratory campaign was performed at the Hydraulic Laboratory of Bologna. The experiments were aimed to analyze the vertical pressure distribution along the crown wall and the resulting wave forces, by varying geometrical and hydraulic parameters. The tested configurations included different off-shore slopes, dike crest widths, crown-wall heights, dike crest freeboards and the inclusion of the parapet. The measurements were combined with the image analysis of the run-up and of the wave impact process. A sub-set of the experiments was numerically reproduced, with the openFOAM modelling suite, to support and to extend the experimental results. The results confirmed the link between the air content, the shape and the magnitude of the pressures according to the breaker type, already observed for larger-scale experiments.

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Numerical study of a planar shock interacting with a cylindrical water column embedded with an air cavity

Journal of Fluid Mechanics ◽

10.1017/jfm.2017.403 ◽

2017 ◽

Vol 825 ◽

pp. 825-852 ◽

Cited By ~ 17

Author(s):

Gaoming Xiang ◽

Bing Wang

Keyword(s):

Shock Wave ◽

Water Column ◽

Numerical Study ◽

Incident Shock ◽

Weno Scheme ◽

Geometrical Parameters ◽

Wave Impact ◽

Planar Shock ◽

Mach Numbers ◽

The Impact

This paper performs a numerical study on the interaction of a planar shock wave with a water column embedded with/without a cavity of different sizes at high Weber numbers. The conservative-type Euler and non-conservative scalar two-equations representing the transportation of two-phase properties consist of the diffusion interface capture models. The numerical fluxes are computed by the Godunov-type Harten-Lax–van Leer contact Riemann solver coupled with an incremental fifth-order weighted essentially non-oscillatory (WENO) scheme. A third-order total variation diminishing (TVD) Runge–Kutta scheme is used to advance the solution in time. The morphology and dynamical characteristics are analysed qualitatively and quantitatively to demonstrate the breakup mechanism of the water column and formation of transverse jets under different incident shock intensities and embedded-cavity sizes. The jet tip velocities are extracted by analysing the interface evolution. The liquid column is prone to aerodynamic breakup with the formation of micro-mist at later stages instead of liquid evaporation because of the weakly heating effects of the surrounding air. It is numerically confirmed that the liquid-phase pressure will drop below the saturated vapour pressure, and the low pressure can be sustained for a certain time because of the focusing of the expansion wave, which accounts for the cavitation inside the liquid water column. The geometrical parameters of the deformed water column are identified, showing that the centreline width decreases but the transverse height increases nonlinearly with time. The deformation rates are nonlinearly correlated under different Mach numbers. The first transverse jet is found for a water column with an embedded cavity, whereas the water hammer shock and second jet do not occur under the impact of low intensity incident shock waves. The $x$-velocity component recorded at the rear stagnation point can remain unchanged for a comparable time after a declined evolution, which indicates that the downstream wall of the shocked water ring somehow moves uniformly. It can be explained that the acceleration of the downstream wall is balanced by the trailing shedding vortex, and this effect is more evident under higher Mach numbers. The increased enstrophy, mainly generated at the interface, demonstrates the competition of the baroclinic effects of the shock wave impact over dilatation.

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Physical and Numerical Investigations on Wave Run-Up and Dissipation under Breakwater with Fence Revetment

Journal of Marine Science and Engineering ◽

10.3390/jmse9121355 ◽

2021 ◽

Vol 9 (12) ◽

pp. 1355

Author(s):

Enjin Zhao ◽

Lin Mu ◽

Zhaoyang Hu ◽

Xinqiang Wang ◽

Junkai Sun ◽

...

Keyword(s):

Wave Height ◽

Water Depth ◽

Significant Wave Height ◽

Irregular Waves ◽

Structure Stability ◽

Wave Impact ◽

Significant Wave ◽

Tide Level ◽

Run Up ◽

The Impact

Revetment elements and protective facilities on a breakwater can effectively weaken the impact of waves. In order to resist storm surges, there is a plan to build a breakwater on the northern shore of Meizhou Bay in Putian City, China. To better design it, considering different environmental conditions, physical and numerical experiments were carried out to accurately study the effects of the breakwater and its auxiliary structures on wave propagation. In the experiments, the influence of the wave type, initial water depth, and the structure of the fence plate are considered. The wave run-up and dissipation, the wave overtopping volume, and the structure stability are analyzed. The results indicate that the breakwater can effectively resist the wave impact, reduce the wave run-up and overtopping, and protect the rear buildings. In addition, under the same still water depth and significant wave height, the amount of overtopped water under regular waves is larger than that under irregular waves. With the increase of the still water depth and significant wave height, the overtopped water increases, which means that when the storm surge occurs, damage on the breakwater under the high tide level is greater than that under the low tide level. Besides, the fence plate can effectively dissipate energy and reduce the overtopping volume by generating eddy current in the cavity. Considering the stability and the energy dissipation capacity of the fence plate, it is suggested that a gap ratio of 50% is reasonable.

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