A Laboratory Study on the Wave Distribution around Breakwater

2012 ◽  
Vol 170-173 ◽  
pp. 2312-2315 ◽  
Author(s):  
Bao Lei Geng ◽  
Ci Heng Zhang ◽  
Yu Fen Cao
Keyword(s):  
Physical Model ◽  
Laboratory Study ◽  
Incident Wave ◽  
Three Dimensional ◽  
Model Tests ◽  
Wave Action ◽  
Wave Basin ◽  
Wave Generator ◽  
Wave Distribution ◽  
Directional Wave

A three-dimensional physical model was used to study the wave distribution around breakwater in Malaysia Kuantan. Model tests were carried out by using the L-type action absorption directional wave generator in a 45m×40m wave basin at TIWTE in Tianjin China. The incident wave conditions were checked first in the laboratory and a series steps were introduced to construct the bathymetry and breakwater structure. At last, the wave distribution around the breakwater with 60yrs and 100yrs wave action were given respectively. The conclusions should be used to achieve optimization of the design.

Three Dimensional Physical Model Study on Penang Fishing Port Project

2014 ◽  
Vol 580-583 ◽  
pp. 2198-2201
Author(s):  
Ci Heng Zhang ◽  
Bao Lei Geng
Keyword(s):  
Physical Model ◽  
Incident Wave ◽  
Three Dimensional ◽  
Model Tests ◽  
Test Results ◽  
Model Study ◽  
Wave Basin ◽  
Wave Generator ◽  
Wave Distribution ◽  
Directional Wave

A three-dimensional physical model was used to study the wave distribution around breakwater in Malaysia Penang. Model tests were carried out by using the L-type action absorption directional wave generator in a 45m×40m wave basin at TIWTE in Tianjin China. The incident wave conditions were checked first in the laboratory and a series steps were introduced to construct the bathymetry and breakwater structure. By comparing the test results, the improved top elevation of breakwater is +4.5m, and the recommendation length of northern part of breakwater is 65m.

scholarly journals PHYSICAL MODELING STUDY ON SCOUR AND SCOUR COUNTERMEASURE FOR SEA-CROSSING BRIDGE PIERS

2012 ◽  
Vol 1 (33) ◽  
pp. 83
Author(s):  
Hsin Hung Chen ◽  
Ray-Yeng Yang ◽  
Ping-Chiao Kuo ◽  
Hwung-Hweng Hwung
Keyword(s):  
Physical Model ◽  
Model Tests ◽  
Bridge Piers ◽  
Test Series ◽  
Model Study ◽  
Sea Bed ◽  
Wave Basin ◽  
Scour Protection ◽  
Hydraulics Laboratory ◽  
Scour Countermeasure

There are significant engineering challenges in placing the sea-crossing bridge piers in more or les shallow coastal waters because, as well as having to withstand storm-force waves and tidal currents, the bridge piers have to remain stable on a sea bed that may be continuously changing. One of the major challenges faced by designers is how to predict, and prevent, scour of the seabed sediments around the sea-crossing bridge piers. This paper describes a physical model study on scour and scour countermeasure for sea-crossing bridge piers. A 1:49 scale movable bed model tests were carried out in the Near-shore Wave Basin (NSWB, 27m x 19m) at the Tainan Hydraulics Laboratory, National Chang Kung University (NCKU), Tainan, Taiwan, with the sea-crossing bridge piers in the test area. Three series of physical model tests were performed in this study. The aim of the first test series is to investigate the maximum scour depth for the initial construction of bridge piers with only one pier model. Then the second test series were conducted to investigate the greatest magnitude of local scour and potential scour area in the sand bed around the sea-crossing bridge group piers with no scour protection. Based on the analysis from the former NSWB experimental results, the suitable scour countermeasure for sea-crossing bridge piers would be proposed and validated its function of preventing scour in the third test series.

Artificial Intelligence and Rubble-Mound Breakwater Stability

2012 ◽  
pp. 1499-1506
Author(s):  
Gregorio Iglesias Rodriguez ◽  
Alberte Castro Ponte ◽  
Rodrigo Carballo Sanchez ◽  
Miguel Ángel Losada Rodriguez
Keyword(s):  
Physical Model ◽  
Model Tests ◽  
Wave Action ◽  
Ann Model ◽  
Climate Conditions ◽  
Wave Flume ◽  
Physical Model Tests ◽  
Rubble Mound ◽  
The Stability ◽  
Rubble Mound Breakwaters

Breakwaters are coastal structures constructed to shelter a harbour basin from waves. There are two main types: rubble-mound breakwaters, consisting of various layers of stones or concrete pieces of different sizes (weights), making up a porous mound; and vertical breakwaters, impermeable and monolythic, habitually composed of concrete caissons. This article deals with rubble-mound breakwaters. A typical rubble-mound breakwater consists of an armour layer, a filter layer and a core. For the breakwater to be stable, the armour layer units (stones or concrete pieces) must not be removed by wave action. Stability is basically achieved by weight. Certain types of concrete pieces are capable of achieving a high degree of interlocking, which contributes to stability by impeding the removal of a single unit. The forces that an armour unit must withstand under wave action depend on the hydrodynamics on the breakwater slope, which are extremely complex due to wave breaking and the porous nature of the structure. A detailed description of the flow has not been achieved until now, and it is unclear whether it will be in the future in view of the turbulent phenomena involved. Therefore the instantaneous force exerted on an armour unit is not, at least for the time being, amenable to determination by means of a numerical model of the flow. For this reason, empirical formulations are used in rubble-mound design, calibrated on the basis of laboratory tests of model structures. However, these formulations cannot take into account all the aspects affecting the stability, mainly because the inherent complexity of the problem does not lend itself to a simple treatment. Consequently the empirical formulations are used as a predesign tool, and physical model tests in a wave flume of the particular design in question under the pertinent sea climate conditions are de rigueur, except for minor structures. The physical model tests naturally integrate all the complexity of the problem. Their drawback lies in that they are expensive and time consuming. In this article, Artificial Neural Networks are trained and tested with the results of stability tests carried out on a model breakwater. They are shown to reproduce very closely the behaviour of the physical model in the wave flume. Thus an ANN model, if trained and tested with sufficient data, may be used in lieu of the physical model tests. A virtual laboratory of this kind will save time and money with respect to the conventional procedure.

Numerical Modelling of Wave Run-Up on a Wind Turbine Foundation

2008 ◽  
Author(s):  
Anders Wedel Nielsen ◽  
Simon Brandi Mortensen ◽  
Vagner Jacobsen ◽  
Erik Damgaard Christensen
Keyword(s):  
Physical Model ◽  
Three Dimensional ◽  
Model Tests ◽  
Offshore Wind ◽  
Offshore Wind Turbines ◽  
Physical Model Tests ◽  
Run Up ◽  
3D Effect ◽  
3D Waves ◽  
Horizontal Bottom

This paper presents the results of a CFD model of the wave run-up on a monopile. The monopile is widely used as the foundation unit for offshore wind turbines. The aim for the calculations is to make a detailed investigation of the effect of three-dimensional (3D) waves on the run-up and to determine the maximum wave run-up. The CFD results are compared with the results of physical model tests conducted under the same conditions. The model tests were conducted under idealized conditions: The tests were carried out on a horizontal bottom using phase and directional focused waves to obtain a 3D effect and at the same time being able to control the breaking. The key objective of this part of the numerical analysis is to develop a model capable of reproducing the results of the physical model tests.

Wave-in-Deck Impulsive Pressure on Unsheltered Jetties Exposed to Waves and Current

2012 ◽  
Vol 256-259 ◽  
pp. 1928-1936
Author(s):  
Yan Qiu Meng ◽  
Guo Ping Chen ◽  
Shi Chang Yan
Keyword(s):  
Physical Model ◽  
Incident Wave ◽  
Offshore Structures ◽  
Model Tests ◽  
Scale Model ◽  
Current Magnitude ◽  
Directional Waves ◽  
Physical Model Tests ◽  
Wave Directionality ◽  
Impulsive Pressure

Impulsive pressure induced by waves is an important factor to be considered in the design of offshore structures. This paper presents results from physical model tests on the impulsive pressure on deck of unsheltered jetties and similar structures exposed to directional waves in the presence of currents. The pressures were measured on a 1:50 scale model of a jetty head with down-standing beams and berthing members. Different incident wave angles, the current velocities and the angles between wave and current were considered to identify the effects of these factors on the impulsive pressures. Data collected from model tests were analyzed to gain insights on the mechanics of the impulsive pressure under different wave and current conditions. It is shown that the impulsive pressure is sensitive to the wave directionality and the current magnitude.

Artificial Intelligence and Rubble-Mound Breakwater Stability

2011 ◽  
pp. 144-150
Author(s):  
Gregorio Iglesias Rodriguez ◽  
Alberte Castro Ponte ◽  
Rodrigo Carballo Sanchez ◽  
Miguel Ángel Losada Rodriguez
Keyword(s):  
Physical Model ◽  
Model Tests ◽  
Wave Action ◽  
Ann Model ◽  
Climate Conditions ◽  
Wave Flume ◽  
Physical Model Tests ◽  
Rubble Mound ◽  
The Stability ◽  
Rubble Mound Breakwaters

Breakwaters are coastal structures constructed to shelter a harbour basin from waves. There are two main types: rubble-mound breakwaters, consisting of various layers of stones or concrete pieces of different sizes (weights), making up a porous mound; and vertical breakwaters, impermeable and monolythic, habitually composed of concrete caissons. This article deals with rubble-mound breakwaters. A typical rubble-mound breakwater consists of an armour layer, a filter layer and a core. For the breakwater to be stable, the armour layer units (stones or concrete pieces) must not be removed by wave action. Stability is basically achieved by weight. Certain types of concrete pieces are capable of achieving a high degree of interlocking, which contributes to stability by impeding the removal of a single unit. The forces that an armour unit must withstand under wave action depend on the hydrodynamics on the breakwater slope, which are extremely complex due to wave breaking and the porous nature of the structure. A detailed description of the flow has not been achieved until now, and it is unclear whether it will be in the future in view of the turbulent phenomena involved. Therefore the instantaneous force exerted on an armour unit is not, at least for the time being, amenable to determination by means of a numerical model of the flow. For this reason, empirical formulations are used in rubble-mound design, calibrated on the basis of laboratory tests of model structures. However, these formulations cannot take into account all the aspects affecting the stability, mainly because the inherent complexity of the problem does not lend itself to a simple treatment. Consequently the empirical formulations are used as a predesign tool, and physical model tests in a wave flume of the particular design in question under the pertinent sea climate conditions are de rigueur, except for minor structures. The physical model tests naturally integrate all the complexity of the problem. Their drawback lies in that they are expensive and time consuming. In this article, Artificial Neural Networks are trained and tested with the results of stability tests carried out on a model breakwater. They are shown to reproduce very closely the behaviour of the physical model in the wave flume. Thus an ANN model, if trained and tested with sufficient data, may be used in lieu of the physical model tests. A virtual laboratory of this kind will save time and money with respect to the conventional procedure.

Prediction of Ship Motions Via a Three-Dimensional Time-Domain Method Following a Quad-Tree Adaptive Mesh Technique

2020 ◽  
Vol 27 (1) ◽  
pp. 29-38
Author(s):  
Teng Zhang ◽  
Junsheng Ren ◽  
Lu Liu
Keyword(s):  
Free Surface ◽  
Incident Wave ◽  
Time Domain ◽  
Three Dimensional ◽  
Adaptive Mesh ◽  
Wave Profile ◽  
Time Domain Method ◽  
Ship Motions ◽  
Quad Tree ◽  
Mesh Technique

AbstractA three-dimensional (3D) time-domain method is developed to predict ship motions in waves. To evaluate the Froude-Krylov (F-K) forces and hydrostatic forces under the instantaneous incident wave profile, an adaptive mesh technique based on a quad-tree subdivision is adopted to generate instantaneous wet meshes for ship. For quadrilateral panels under both mean free surface and instantaneous incident wave profiles, Froude-Krylov forces and hydrostatic forces are computed by analytical exact pressure integration expressions, allowing for considerably coarse meshes without loss of accuracy. And for quadrilateral panels interacting with the wave profile, F-K and hydrostatic forces are evaluated following a quad-tree subdivision. The transient free surface Green function (TFSGF) is essential to evaluate radiation and diffraction forces based on linear theory. To reduce the numerical error due to unclear partition, a precise integration method is applied to solve the TFSGF in the partition computation time domain. Computations are carried out for a Wigley hull form and S175 container ship, and the results show good agreement with both experimental results and published results.

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