scholarly journals STORM-DRIVEN WAVE IMPACT LOADS AND SCOUR AT A BEACH SEAWALL

2020 ◽  
pp. 30
Author(s):  
Sylvain Perrin ◽  
Thomas Saillour ◽  
Elodie Baillit
Keyword(s):  
Physical Model ◽  
Wave Force ◽  
Development Project ◽  
Impact Loads ◽  
Force Measurements ◽  
Wave Impact ◽  
Pros And Cons ◽  
Model Versus ◽  
Hydraulics Laboratory ◽  
Force Intensity

The Grande-Motte port and seafront development project on the French Mediterranean coastline entailed evaluating wave impact loads (pressures and forces) on the new beach seawall and comparing the resulting scour potential at the base of the existing and new seawall. A physical model was built at ARTELIA's hydraulics laboratory in Grenoble (France) to provide insight into: wave and setup at the beach, the evolution of scour over time at the front of the wall, quasi-static and impulsive wave force intensity and distribution on the wall, and water and sand overtopping discharges over the wall. Light-weight sediment physical model and pressure and force measurements were performed with scale 1:18. The paper will discuss the pros and cons of a physical model versus numerical/ empirical modelsRecorded Presentation from the vICCE (YouTube Link): https://youtu.be/AeW3SPwDtVg

Wave Impact Loads on the Bottom of Flat Decks

2021 ◽  
Author(s):  
Daniel de Oliveira Costa ◽  
Julia Araújo Perim ◽  
Bruno Guedes Camargo ◽  
Joel Sena Sales Junior ◽  
Antonio Carlos Fernandes ◽  
...  
Keyword(s):  
Scale Effects ◽  
Offshore Structures ◽  
Model Tests ◽  
Analytical Models ◽  
Navier Stokes ◽  
Impact Loads ◽  
Wave Impact ◽  
Wave Channel ◽  
Waves And Currents ◽  
The Impact

Abstract Slamming events due to wave impact on the underside of decks might lead to severe and potentially harmful local and/or global loads in offshore structures. The strong nonlinearities during the impact require a robust method for accessing the loads and hinder the use of analytical models. The use of computation fluid dynamics (CFD) is an interesting alternative to estimate the impact loads, but validation through experimental data is still essential. The present work focuses on a flat-bottomed model fixed over the mean free surface level submitted to regular incoming waves. The proposal is to reproduce previous studies through CFD and model tests in a different reduced scale to provide extra validation and to identify possible non-potential scale effects such as air compressibility. Numerical simulations are performed in both experiments’ scales. The numerical analysis is performed with a marine dedicated flow solver, FINE™/Marine from NUMECA, which features an unsteady Reynolds-averaged Navier-Stokes (URANS) solver and a finite volume method to build spatial discretization. The multiphase flow is represented through the Volume of Fluid (VOF) method for incompressible and nonmiscible fluids. The new model tests were performed at the wave channel of the Laboratory of Waves and Currents (LOC/COPPE – UFRJ), at the Federal University of Rio de Janeiro.

Distribution of Wave Impact Forces From Breaking and Non-Breaking Waves

2009 ◽  
Author(s):  
Anne M. Fullerton ◽  
Thomas C. Fu ◽  
Edward S. Ammeen
Keyword(s):  
Free Surface ◽  
Wave Height ◽  
Breaking Waves ◽  
Qualitative Assessment ◽  
Total Force ◽  
Impact Loads ◽  
Wave Impact ◽  
Data Set ◽  
Wave Characteristics ◽  
Wide Range

Impact loads from waves on vessels and coastal structures are highly complex and may involve wave breaking, making these changes difficult to estimate numerically or empirically. Results from previous experiments have shown a wide range of forces and pressures measured from breaking and non-breaking waves, with no clear trend between wave characteristics and the localized forces and pressures that they generate. In 2008, a canonical breaking wave impact data set was obtained at the Naval Surface Warfare Center, Carderock Division, by measuring the distribution of impact pressures of incident non-breaking and breaking waves on one face of a cube. The effects of wave height, wavelength, face orientation, face angle, and submergence depth were investigated. A limited number of runs were made at low forward speeds, ranging from about 0.5 to 2 knots (0.26 to 1.03 m/s). The measurement cube was outfitted with a removable instrumented plate measuring 1 ft2 (0.09 m2), and the wave heights tested ranged from 8–14 inches (20.3 to 35.6 cm). The instrumented plate had 9 slam panels of varying sizes made from polyvinyl chloride (PVC) and 11 pressure gages; this data was collected at 5 kHz to capture the dynamic response of the gages and panels and fully resolve the shapes of the impacts. A Kistler gage was used to measure the total force averaged over the cube face. A bottom mounted acoustic Doppler current profiler (ADCP) was used to obtain measurements of velocity through the water column to provide incoming velocity boundary conditions. A Light Detecting and Ranging (LiDAR) system was also used above the basin to obtain a surface mapping of the free surface over a distance of approximately 15 feet (4.6 m). Additional point measurements of the free surface were made using acoustic distance sensors. Standard and high-speed video cameras were used to capture a qualitative assessment of the impacts. Impact loads on the plate tend to increase with wave height, as well as with plate inclination toward incoming waves. Further trends of the pressures and forces with wave characteristics, cube orientation, draft and face angle are investigated and presented in this paper, and are also compared with previous test results.

scholarly journals PHYSICAL MODEL EXPERIMENTS OF ORDU-GIRESUN AIRPORT, TURKEY

2017 ◽  
pp. 16
Author(s):  
Sukru Emrah ARIKAN ◽  
Nurgul GULTEKIN ◽  
Alp Kucukosmanoglu ◽  
Berguzar Ozbahceci ◽  
Mehmet SAG ◽  
...  
Keyword(s):  
Physical Model ◽  
Cross Sections ◽  
Transportation Network ◽  
Design Stage ◽  
Model Experiments ◽  
Model Studies ◽  
Engineering Studies ◽  
Wave Characteristics ◽  
Hydraulics Laboratory ◽  
Structural Aspects

Ordu-Giresun Airport, which has been constructed recently, being an example of the aviation sector of Turkish transportation network, is a project having marine structural aspects due to the construction at the sea by filling and in this workout physical model experiments of the project are evaluated. 3000-meters-long runway and the other superstructures of the airport, the first example of construction of such a structure by filling in the sea in Turkey, is to be protected by a breakwater of 7435 meters long. ‘First Cross Section’ has been prepared by using experimental formulas and artificial neural network and ‘Second Cross Section’, being the alternative of the first one has been planned. Yet, both cross sections have similar characteristics, they have berm heights in such a manner that ‘First Cross Section’ enables the structure to be constructed from the sea, whereas ‘Second Cross Section’ makes it possible from the land. Both cross sections are aimed to be evaluated in terms of stability, wave overtopping and economy through the hydraulic model studies performed at the Hydraulics Laboratory of Turkish Ministry of Transportation, Maritime Affairs and Communication. Starting from design stage (computation of design wave characteristics, physical model experiment under different wave conditions on different structure alternatives) to construction stage the engineering studies is presented with comparisons and discussions.

scholarly journals Wave Impact Loads on Vertical Seawalls: Effects of the Geometrical Properties of Recurve Retrofitting

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2849
Author(s):  
Shudi Dong ◽  
Md Salauddin ◽  
Soroush Abolfathi ◽  
Jonathan Pearson
Keyword(s):  
Impact Force ◽  
Vertical Wall ◽  
Impact Loads ◽  
Geometrical Shape ◽  
Wave Loading ◽  
Wave Impact ◽  
Static Loads ◽  
Geometrical Properties ◽  
Overhang Length ◽  
Overturning Moment

This study investigates the variation of wave impact loads with the geometrical configurations of recurve retrofits mounted on the crest of a vertical seawall. Physical model tests were undertaken in a wave flume at the University of Warwick to investigate the effects of the geometrical properties of recurve on the pressure distribution, overall force, and overturning moment at the seawall, subject to both impulsive and non-impulsive waves. Additionally, the wave impact and quasi-static loads on the recurve portion of the retrofitted seawalls are investigated to understand the role of retrofitting on the structural integrity of the vertical seawall. Detailed analysis of laboratory measurements is conducted to understand the effects of overhang length and height of the recurve wall on the wave loading. It is found that the increase in both recurve height and overhang length lead to the increase of horizontal impact force at an average ratio of 1.15 and 1.1 times larger the reference case of a plain vertical wall for the tested configurations. The results also show that the geometrical shape changes in recurve retrofits, increasing the overturning moment enacted by the wave impact force. A relatively significant increase in wave loading (both impact and quasi-static loads) are observed for the higher recurve retrofits, while changes in the overturning moment are limited for the retrofits with longer overhang length. The data generated from the physical modelling measurements presented in this study will be particularly helpful for a range of relevant stakeholders, including coastal engineers, infrastructure designers, and the local authorities in coastal regions. The results of this study can also enable scientists to design and develop robust decision support tools to evaluate the performance of vertical seawalls with recurve retrofitting.

scholarly journals An Experimental Investigation of Ride Control Algorithms for High-Speed Catamarans Part 2: Mitigation of Wave Impact Loads

2017 ◽  
Vol 61 (2) ◽  
pp. 51-63 ◽  
Author(s):  
Javad AlaviMehr ◽  
Jason Lavroff ◽  
Michael R. Davis ◽  
Damien S. Holloway ◽  
Giles A. Thomas
Keyword(s):  
Experimental Investigation ◽  
High Speed ◽  
Control Algorithms ◽  
Impact Loads ◽  
Wave Impact ◽  
Ride Control

scholarly journals Structural vehicle impact loading

2013 ◽  
Vol 11 (3) ◽  
pp. 285-292
Author(s):  
Dragoslav Stojic ◽  
Stefan Conic
Keyword(s):  
Impact Analysis ◽  
Impact Loads ◽  
Structural Elements ◽  
Structural Element ◽  
Static Loads ◽  
Equivalent Static Loads ◽  
Vehicle Impact ◽  
Dynamic Forces ◽  
Force Intensity

In contemporary design, vehicle impact into the structures is paid great attention since they can be dominant, depending on the type of structure. The key issue in the vehicle impact analysis is the proper determination of intensity and way of action of dynamic forces on the structural element and its behavior after the imparted load. The Eurocodes, in the annexes provide recommendations for determination of force intensity depending on mass and velocity of the colliding vehicle. Equivalent static loads causing approximate effects on the structural elements are used as quite approximate and efficient methods. The paper comprises the analysis of deformation of columns having the same characteristics, exposed to impact loads via the equivalent static loads, depending on the stress state in columns, and a comparative analysis has been done.

Response of Metal Building Cladding to Tsunami Wave Impact Loads

2020 ◽  
Vol 146 (11) ◽  
pp. 04020236
Author(s):  
Christine Baker ◽  
Christopher Higgins ◽  
Judy Liu ◽  
Harry Yeh
Keyword(s):  
Tsunami Wave ◽  
Impact Loads ◽  
Wave Impact ◽  
Metal Building

scholarly journals Kinerja Model Fisik Konverter Energi Ombak Rangkaian Gear Searah pada Periode Ombak yang Bervariasi

2016 ◽  
Vol 22 (2) ◽  
pp. 71 ◽  
Author(s):  
Masjono Muchtar ◽  
Salama Manjang ◽  
Dadang A Suriamiharja ◽  
M Arsyad Thaha
Keyword(s):  
Physical Model ◽  
Wave Energy ◽  
Ocean Waves ◽  
Wave Energy Converter ◽  
Wave Period ◽  
Physical Model Test ◽  
Energy Converter ◽  
Wave Flume ◽  
Period Variations ◽  
Hydraulics Laboratory

To date there were few research on the effect of non-linearity properties of the ocean waves on the performance of wave energy converter (WEC), which uses a series of unidirectional gear. One such parameter is the variation of wave period. The influence of wave period variations on the performance of physical model of the wave energy converters have been investigated at the Hydraulics Laboratory, Department of Civil Engineering, Hasanuddin University Indonesia. This WEC physical model was fabricated and assembled at Politeknik ATI Makassar Indonesia. The investigation steps consists of physical model development, physical model investigation at wave flume prior to the wave period  variation, measuring input output parameters of the physical model under test and empirical model formulation based on observed data analysis. Physical model test carried out on the wave flume at the Hydraulics Laboratory of the Department of Civil Hasanuddin University, at a water depth of 25 cm, wave height between 5-9 cm and wave period between 1.2 - 2.2 seconds. Investigation result based on flywheel radial speed (RPM) and torque (Nm) indicated that calculated harvested power was inversely proportional with the wave period. The longer the period of the waves, the energy produced is getting smaller. The derived empirical formula was y = -85.598x + 208.53 and R² = 0.8881. Y is energy produced (Watt) and X is the wave period (Second). Formulations generated from this study could be used as a reference for future research in dealing with wave period variations on a design one way gear wave energy converter as a source of renewable energy.

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

2018 ◽  
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.

Prediction of Wave-in-Deck Forces on Fixed Jacket-Type Structures Based on CFD Calculations

2008 ◽  
Author(s):  
Benedicte Brodtkorb
Keyword(s):  
Initial Phase ◽  
Central Element ◽  
Load Level ◽  
Impact Loads ◽  
Extreme Waves ◽  
Original Design ◽  
Wave Impact ◽  
Cfd Simulations ◽  
Simplified Method ◽  
Horizontal Wave

The original design requirement for positive air gap is no longer fulfilled for a number of jacket-type structures still in production. When extreme waves impact the deck, the total loads on the structure are increased significantly, so accurate prediction of wave-in-deck forces is a central element in structural reassessment. Simplified methods for evaluating maximum horizontal and vertical loads are useful in an initial phase. In this study, we compare numerical prediction using CFD with the simplified API method for horizontal wave-in-deck load. The global wave impact loads for 0° head-on and 45° oblique waves are calculated for various deck configurations, all heavily equipped (solid). The effect of current is also addressed. In the case of no current, we found that the CFD simulations generally display a reasonable load level compared with the API load method. However, the CFD calculations indicate that the simplified method should be used with care for situations with large upwelling of water and decks with multiple deck girders. A simplified method for predicting vertical wave-in-deck loads on solid decks is developed. The method, first published in DNV-RP-C205, aims to be useful in an initial phase of reassessment.

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