scholarly journals Roughness coefficient of polyurethane-bonded revetment

2019 ◽  
Vol 1 (2) ◽  
pp. Manuscript ◽  
Author(s):  
Tanapon Rattharangsri ◽  
Effi Helmy Ariffin ◽  
Nor Aslinda Awang ◽  
Qi Hongshuai
Keyword(s):  
Standard Deviation ◽  
Laboratory Testing ◽  
Roughness Coefficient ◽  
Regular Wave ◽  
Video Cameras ◽  
Wave Basin ◽  
Wave Generator ◽  
Run Up

This article analyzed a roughness coefficient of a polyurethane-bonded revetment (PBR) by laboratory testing. A wave basin was constructed with a regular wave generator installed. Three types of revetment were constructed at the same time in the wave basin. Scales were painted on the revetments. Video cameras were installed to record the wave run-up. Three revetment slopes were tested. The roughness coefficient of the PBR was found to be in the range of 0.632-0.674 with the standard deviation of 0.042-0.053. After the roughness coefficient of the PBR is known, coastal engineers can now design the revetment’s crest elevation with confidence.

scholarly journals OBSERVATIONS OF BEACH-DUNE MORPHOGOLICAL RESPONSE TO STORM WAVES USING LIDAR BATHYMETRIC MAPPING IN A WAVE BASIN

2018 ◽  
pp. 5
Author(s):  
Ramy Y. Marmoush ◽  
Ryan P. Mulligan
Keyword(s):  
Laser Scanning ◽  
Sand Dune ◽  
Dune System ◽  
Sand Beach ◽  
Coastal Morphology ◽  
3 Dimensional ◽  
Storm Waves ◽  
Impact Scale ◽  
Wave Basin ◽  
Run Up

Waves during major storms can cause significant changes to coastal morphology (Lee et al., 1998). The beach-dune system is known to be highly vulnerable to erosion when the wave run-up exceeds the threshold of the base of the dune in the collision regime, according to the Storm Impact scale defined by Sallenger (2000). Detailed bathymetric measurements are very difficult to obtain during storms due to the hazardous wave conditions. However, bathymetric surveys can be easily and intermittently performed during smaller scale physical model experiments (e.g., Hamilton et al., 2001) and high resolution can be achieved using laser scanning with Light Detection and Ranging (LIDAR) sensors (Smith et al., 2017). In the present study, a laboratory experiment of beach-dune morphology change is conducted in a rectangular wave basin that has recently been used to simulate erosion of a 2-dimensional sand dune (Berard et al., 2017). The objective of the present study is to investigate the 3-dimensional morphologic response of a sand beach-dune system to storm waves approaching at an oblique angle.

The Content of IMF Staff Reports for Euro Area Countries

2014 ◽  
pp. 272-292
Author(s):  
Lena Golubovskaja
Keyword(s):  
Standard Deviation ◽  
Euro Area ◽  
Mean Value ◽  
Systematic Bias ◽  
Executive Board ◽  
Sample Mean ◽  
Warning Tone ◽  
The Mean ◽  
Run Up ◽  
The Imf

This chapter analyzes the tone and information content of the two external policy reports of the Internal Monetary Fund (IMF), the IMF Article IV Staff Reports, and Executive Board Assessments for Euro area countries. In particular, the researchers create a tone measure denoted WARNING based on the existing DICTION 5.0 Hardship dictionary. This study finds that in the run-up to the current credit crises, average WARNING tone levels of Staff Reports for Slovenia, Luxembourg, Greece, and Malta are one standard deviation above the EMU sample mean; and for Spain and Belgium, they are one standard deviation below the mean value. Furthermore, on average for Staff Reports over the period 2005-2007, there are insignificant differences between the EMU sample mean and Staff Reports’ yearly averages. Researchers find the presence of a significantly increased level of WARNING tone in 2006 (compared to the previous year) for the IMF Article IV Staff Reports. There is also a systematic bias of WARNING scores for Executive Board Assessments versus WARNING scores for the Staff Reports.

Predicted wave field in a laboratory wave basin

1990 ◽  
Vol 17 (6) ◽  
pp. 1005-1014 ◽  
Author(s):  
Michael Isaacson ◽  
Shiqin Qu
Keyword(s):  
Wave Field ◽  
Wave Diffraction ◽  
Diffraction Theory ◽  
Ocean Engineering ◽  
Laboratory Facilities ◽  
Rectangular Basin ◽  
Diffraction Wave ◽  
Wave Basin ◽  
Wave Generator ◽  
Reflection Boundary

The present paper describes a numerical method for predicting the wave field produced by a segmented wave generator undergoing specified motions in a wave basin which may contain partially reflecting sides. The approach used is based on linear diffraction theory and utilizes a point source representation of the generator segments and any reflecting walls that are present. The method involves the application of a partial reflection boundary condition, which is discussed. Numerical results are presented for the propagating wave field due to specified wave generator motions in a rectangular basin. Cases that are considered include both perfectly absorbing and partially reflecting beaches along the basin sides, as well as the presence of perfectly reflecting short sidewalls near the generator. The method appears able to account adequately for the effects of wave diffraction and partial reflections, and to predict the generated wave field realistically. Key words: coastal engineering, hydrodynamics, laboratory facilities, ocean engineering, wave diffraction, wave generation, wave reflection.

scholarly journals WAVE RUN-UP PREDICTION VS. MODEL TEST RESULTS: A COMPARISON

1988 ◽  
Vol 1 (21) ◽  
pp. 47 ◽  
Author(s):  
Peter E. Gadd ◽  
Victor Manikian ◽  
Jerry L. Machemehl
Keyword(s):  
Physical Model ◽  
Model Test ◽  
Large Scale ◽  
Physical Model Test ◽  
Roughness Coefficient ◽  
Wave Steepness ◽  
Test Results ◽  
Shore Protection ◽  
Run Up

Large-scale physical model test measurements of wave run-up are compared with wave run-up prediction derived from the Shore Protection Manual (SPM). Noteworthy discrepancies between the results of these two methods have been identified that include substantial overestimation of wave run-up elevations using the SPM approach, and computation of roughness coefficient values that vary as a function of wave steepness. The slope armors tested in the study at model scales of 1:3 and 1:4 include linked concrete matting and overlapped gravel-filled fabric bags.

3D Numerical Wave Basin Based on Parallelized SPH Method

2014 ◽  
Author(s):  
Hongjie Wen ◽  
Bing Ren
Keyword(s):  
Solitary Wave ◽  
Smoothed Particle Hydrodynamics ◽  
Large Diameter ◽  
Regular Wave ◽  
Sph Method ◽  
Submerged Breakwater ◽  
Wave Basin ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Numerical Wave

A viscous 3D numerical wave basin for high nonlinear waves was developed based on Smoothed Particle Hydrodynamics (SPH) method. The computational accuracy of SPH method is mainly improved by introducing the Corrective Smoothed Particle Hydrodynamics Method (CSPM) and a novel pressure correction scheme. The incident waves are generated from the inflow boundary by prescribing a velocity profile of the flap-type wavemaker motions, and the outgoing waves are numerically dissipated inside an artificial damping zone located at the end of the basin. Moreover, the parallelization of the improved 3D SPH scheme has been carried out using a hybrid MPI-OpenMP programming, together with a dynamic load balancing strategy to improve the computational efficiency. The generation and propagation of regular wave and solitary wave have been simulated. Wave forces induced by regular wave acting on a large-diameter circular cylinder and solitary wave passing over a submerged breakwater are also presented to verify the accuracy of SPH model. In addition, several computing cases of different particle resolutions are investigated and a high parallel efficiency is obtained.

scholarly journals DESIGN OF A POWERFUL AND PORTABLE MULTIDIRECTIONAL WAVEMA

2017 ◽  
pp. 29
Author(s):  
Andrew Malcolm Cornett ◽  
Peter Laurich ◽  
Enrique Gardeta ◽  
Daniel Pelletier
Keyword(s):  
National Research Council ◽  
Side Wall ◽  
Wave Basin ◽  
Wave Generator ◽  
Wave Heights ◽  
Regenerative Power ◽  
Active Wave ◽  
Multidirectional Wave ◽  
And Control ◽  
New Machine

A new multidirectional wave generator with 72 independent paddles has been designed, fabricated and commissioned at the National Research Council labs in Ottawa, Canada. The wet-back piston-mode machine is installed in a new 50 m long by 30 m wide rectangular wave basin, where water depths can be varied over the range from 0 m up to 1.3 m. The new machine is believed to be unique in the world in that it combines the power and stroke required to generate multidirectional spectral wave conditions with significant wave heights exceeding 0.4 m together with the modularity and ease of portability required to move the machine quickly and safely to new positions. The new machine can also be sub-divided to form several shorter machines if desired. The new wave generator features lightweight, composite materials, energy efficient regenerative power supplies, state-of-the-art software and control systems, including capabilities for active wave absorption (reflection compensation), second-order wave generation for improved generation of nonlinear sub- and super-harmonics, side-wall reflection, and more. The design of this new directional wavemaker is described and several of the more innovative features are highlighted in this paper.

scholarly journals THE EFFECT OF WAVE ENERGY SPECTRA ON WAVE RUN-UP

1968 ◽  
Vol 1 (11) ◽  
pp. 57 ◽  
Author(s):  
J.H. Van Oorschot ◽  
K. D'Angremond
Keyword(s):  
Energy Spectrum ◽  
Wave Energy ◽  
Irregular Waves ◽  
Energy Spectra ◽  
Wave Spectra ◽  
Hydraulic Actuators ◽  
Wave Generator ◽  
Run Up ◽  
Hydraulics Laboratory ◽  
Monochromatic Waves

Previous investigations carried out "by the Delft Hydraulics laboratory have shown the necessity of applying irregular waves m studies on wave run-up. The installation of a wave generator driven "by hydraulic actuators has created the possibility of producing irregular waves with arbitrary wave spectra. Investigations performed with this type of wave generator show the influence of the shape of the energy spectrum on the wave run-up on smooth straight slopes of 1:4 and 1:6. The results are compared with run-up figures derived from experiments with wind generated waves and with monochromatic waves.

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.

Numerical Simulation of Wave Overtopping Based on DualSPHysics

2013 ◽  
Vol 405-408 ◽  
pp. 1463-1471 ◽  
Author(s):  
Xing Ye Ni ◽  
Wei Bin Feng
Keyword(s):  
Numerical Simulation ◽  
Vertical Wall ◽  
Breaking Waves ◽  
Numerical Wave Tank ◽  
Regular Wave ◽  
Average Deviation ◽  
Wave Overtopping ◽  
Different Types ◽  
Numerical Wave ◽  
Run Up

To obtain a more detailed description of wave overtopping, a 2-D numerical wave tank is presented based on an open-source SPH platform named DualSPHysics, using a source generation and absorption technology suited for SPH methods with analytical relaxation approach. Numerical simulation of regular wave run-up and overtopping on typical sloping dikes is carried out and satisfactory agreements are shown between numerical results and experimental data. Another overtopping simulation of regular wave is conducted against six different types of seawalls (vertical wall, curved wall, recurved wall, 1:3 slope with smooth face, 1:1.5 slope with smooth face and 1:1.5 slope with stepped-face), which represents the details of various breaking waves interacting with different seawalls, and the average deviation of wave overtopping rate is 6.8%.

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