scholarly journals HONOLULU REEF RUNWAY DIKE

1970 ◽  
Vol 1 (12) ◽  
pp. 99
Author(s):  
Robert Q. Palmer ◽  
James R. Walker
Keyword(s):  
Water Depth ◽  
Water Surface ◽  
Breaking Waves ◽  
Model Tests ◽  
Transmitted Wave ◽  
Bottom Slope ◽  
Wave Runup ◽  
Wave Flume ◽  
Economical Design ◽  
Wave Heights

Criteria for design of a wave barrier to protect the proposed Honolulu International Airport Reef Runway from breaking waves were developed in wave flume model tests Structures with tribar and quarrystone armor units placed in single and multiple layers, on homogeneous and composite slopes, were subjected to both overtopping and non-overtopping breaking waves Data on wave runup, armor unit stability, quantities of overtopping water, and transmitted wave heights were obtained using a 1 50 bottom slope, which modeled the irregular coral bathymetry seaward of the proposed structure The model to prototype scale ratios ranged from 1 5 to 1 35 Model Tests indicated that the weight of armor units placed below one-third the water depth may be three-fourths that of the units located near the water surface It was noted that the maximum wave runup was 1 8 times the water depth fronting the structure Data were obtained concerning quantities of overtopping water and transmitted wave heights over the low barriers The study augments available criteria for economical design of structures subjected to breaking waves.

The evolution of large non-breaking waves in intermediate and shallow water. I. Numerical calculations of uni-directional seas

2010 ◽  
Vol 467 (2127) ◽  
pp. 778-805 ◽  
Author(s):  
V. Katsardi ◽  
C. Swan
Keyword(s):  
Water Depth ◽  
Wave Train ◽  
Breaking Waves ◽  
Numerical Calculations ◽  
Linear Wave ◽  
Frequency Spectra ◽  
Relative Significance ◽  
Relative Water ◽  
Wave Heights ◽  
Wave Models

In deep water it is well known that the evolution of the largest waves in realistic, broad-banded frequency spectra is governed by dispersive focusing. However, as the water depth reduces this process weakens and the relative significance of wave modulation is shown to be increasingly important. This leads to very different extreme wave groups, the properties of which are critically dependent upon the local nonlinearity. To explore these effects, and to provide a physical explanation for their occurrence, two complementary wave models are employed. The combined numerical results show that the nature of large uni-directional waves varies depending on the relative water depth. As the water depth reduces, both the bound and resonant interactions become more significant. However, the third-order resonant terms have the most profound influence. By modifying both the amplitude and phase of the underlying linear wave components, the largest waves arise as a local instability within a truncated quasi-regular wave train; the latter appearing because of an initial narrowing of the underlying frequency spectrum. Furthermore, the numerical calculations show that, with large changes in both the spectral shape and the phasing of the wave components, both the maximum crest elevations and wave heights are less than those predicted by linear theory.

scholarly journals TRANSMISSION OF REGULAR WAVES PAST FLOATING PLATES

1974 ◽  
Vol 1 (14) ◽  
pp. 112
Author(s):  
Uygur Sendil ◽  
W.H. Graf
Keyword(s):  
Water Depth ◽  
Wave Length ◽  
Wave Theory ◽  
Finite Amplitude ◽  
Linear Wave ◽  
Regular Waves ◽  
Transmission Coefficients ◽  
Wave Flume ◽  
Wave Heights ◽  
Incident Waves

Theoretical solutions for the transmission beyond and reflection of waves from fixed and floating plates are based upon linear wave theory, as put forth by John (1949), and Stoker (1957), according to which the flow is irrotational, the fluid is incompressible and frictionless, and the waves are of small amplitude. The resulting theoretical relations are rather complicated, and furthermore, it is assumed that the water depth is very small in comparison to the wave length. Wave transmissions beyond floating horizontal plates are studied in a laboratory wave flume. Regular (harmonic) waves of different heights and periods are generated. The experiments are carried out over a range of wave heights from 0.21 to 8.17 cm (0.007 to 0.268 ft), and wave periods from 0.60 to 4.00 seconds in water depth of 15.2, 30.5, and 45.7 cm (0.5, 1.0 and 1.5 ft). Floating plates of 61, 91 and 122 cm (2, 3 and 4 ft) long were used. From the analyses of regular waves it was found that: (1) the transmission coefficients, H /H , obtained from the experiments are usually less than those obtained from the theory. This is due to the energy dissipation by the plate, which is not considered in the theory. (2) John's (1949) theory predicts the transmission coefficients, H /H , reasonably well for a floating plywood plate, moored to the bottom and under the action of non-breaking incident waves of finite amplitude. (3) a floating plate is less effective in damping the incident waves than a fixed plate of the same length.

Experimental Study on Changes of Sloping Sandy Bed Profile under Breaking Waves

2012 ◽  
Vol 212-213 ◽  
pp. 163-168
Author(s):  
Yun Pan ◽  
Yong Zhou Cheng ◽  
Qing Feng Li ◽  
Wen Cheng Wang
Keyword(s):  
Wave Breaking ◽  
Orbital Motion ◽  
Breaking Waves ◽  
Coastal Structures ◽  
Wave Flume ◽  
Sand Ripple ◽  
Wide Range ◽  
Wave Heights ◽  
Formation And Evolution ◽  
Sand Bar

The wave breaking forces can exacerbate sediment transport, and lead to erosion of the seabed, coastal deformation and destruction of coastal structures. The experiment is carried out in a wave flume with a 1:30 sloping sandy seabed. A wide range of measurements from the regular wave runs are reported, including time series of wave heights, changes of bed profile. The video records are analysed to measure the time development of the seabed form and the characteristics of the orbital motion of the sand in the wave breaking region. The location and wave height at wave breaking point is measured by experiment. Formation and evolution of sand ripple and sand bar are studied under the breaking waves. It is found that effect of bed surface on wave breaking zone is more significant than wave non-breaking.

Experimental Study of Scour Due to Breaking Waves in Front of Vertical-Wall Breakwaters

2004 ◽  
Author(s):  
Ali Hasanzadeh Daloui ◽  
Mirmosadegh Jamali
Keyword(s):  
Experimental Study ◽  
Empirical Equation ◽  
Vertical Wall ◽  
Breaking Waves ◽  
Scour Depth ◽  
Regular Waves ◽  
Factors Affecting ◽  
Wave Flume ◽  
Wave Heights

Scour is an important cause of instability of breakwaters. In case of vertical-wall breakwaters, toe scour can cause collapse of the whole structure. This paper is concerned with an experimental study of the effects of regular breaking waves on scour at toe of vertical-wall breakwaters. Experiments were carried out in a wave flume with regular waves for two cases of a beach with and without a breakwater. Bed profiles and scour depths for various wave heights, periods and depths were recorded. For the case of a beach without a breakwater, the observed bed profile types are compared to predictions. For the case of a beach with a breakwater, factors affecting the scour are investigated, and an empirical equation for scour depth at toe of a vertical wall is proposed.

scholarly journals MODEL TESTS WITH DIRECTLY REPRODUCED NATURE WAVE TRAINS

1974 ◽  
Vol 1 (14) ◽  
pp. 20 ◽  
Author(s):  
Helge Gravesen ◽  
Ebbe Fredericksen ◽  
Jens Kirkegaard
Keyword(s):  
Wave Model ◽  
Short Wave ◽  
Model Tests ◽  
Wave Forces ◽  
Wave Direction ◽  
Incoming Wave ◽  
Irregular Wave ◽  
Wave Flume ◽  
Wave Heights ◽  
Stability Of Structures

Hydraulic model tests are still recognized as the best and in many cases the only tool, indeed, for investigations of design criteria for harbours concerning a) the effect of wave disturbance on moored ships in harbour basins and at offshore terminals, b) stability of structures and wave forces on structures. Model tests with waves have until recently usually been made with regular waves varying the wave height, wave period, wave direction for each test run. An important improvement in the model technique has been the development of irregular wave generators, capable of generating waves directly from nature wave records. The following aspects are presented below 1) A discussion on the methodology of wave model tests. 2) A method for direct reproduction of nature wave records. 3) A method for determining the incoming wave heights in a short wave flume with a reflecting structure and reflection from the wave generator paddle.

Resistance Tests of an Articulated Pusher Barge System in Deep and Shallow Water

2021 ◽  
Author(s):  
Li Zhang ◽  
Lei Xing ◽  
Mingyu Dong ◽  
Weimin Chen
Keyword(s):  
Shallow Water ◽  
Water Depth ◽  
Deep Water ◽  
Water Resistance ◽  
Model Tests ◽  
System 2 ◽  
Changing Trend ◽  
The Difference ◽  
Transport Vessel ◽  
Resistance Performance

Abstract Articulated pusher barge vessel is a short-distance transport vessel with good economic performance and practicability, which is widely used in the Yangtze River of China. In this present work, the resistance performance of articulated pusher barge vessel in deep water and shallow water was studied by model tests in the towing tank and basin of Shanghai Ship and Shipping Research Institute. During the experimental investigation, the articulated pusher barge vessel was divided into three parts: the pusher, the barge and the articulated pusher barge system. Firstly, the deep water resistance performance of the articulated pusher barge system, barge and the pusher at design draught T was studied, then the water depth h was adjusted, and the shallow water resistance at h/T = 2.0, 1.5 and 1.2 was tested and studied respectively, and the difference between deep water resistance and shallow water resistance at design draught were compared. The results of model tests and analysis show that: 1) in the study of deep water resistance, the total resistance of the barge was larger than that of the articulated pusher barge system. 2) for the barge, the shallow water resistance increases about 0.4–0.7 times at h/T = 2.0, 0.5–1.1 times at h/T = 1.5, and 0.7–2.3 times at h/T = 1.2. 3) for the pusher, the shallow water resistance increases about 1.0–0.4 times at h/T = 2.7, 1.2–0.9 times at h/T = 2.0, and 1.7–2.4 times at h/T = 1.6. 4) for the articulated pusher barge system, the shallow water resistance increases about 0.2–0.3 times at h/T = 2.0, 0.5–1.3 times at h/T = 1.5, and 1.0–3.5 times at h/T = 1.2. Furthermore, the water depth Froude number Frh in shallow water was compared with the changing trend of resistance in shallow water.

Fluid-structure interaction computational analysis and experiments of tsunami bore forces on coastal bridges

2021 ◽  
Vol 31 (5) ◽  
pp. 1373-1395
Author(s):  
Iman Mazinani ◽  
Mohammad Mohsen Sarafraz ◽  
Zubaidah Ismail ◽  
Ahmad Mustafa Hashim ◽  
Mohammad Reza Safaei ◽  
...  
Keyword(s):  
Tsunami Wave ◽  
Numerical Study ◽  
Fluid Structure Interaction ◽  
Indian Ocean Tsunami ◽  
Fluid Structure ◽  
Content Type ◽  
Coastal Bridges ◽  
Structure Interaction ◽  
Wave Flume ◽  
Wave Heights

Purpose Two disastrous Tsunamis, one on the west coast of Sumatra Island, Indonesia, in 2004 and another in North East Japan in 2011, had seriously destroyed a large number of bridges. Thus, experimental tests in a wave flume and a fluid structure interaction (FSI) analysis were constructed to gain insight into tsunami bore force on coastal bridges. Design/methodology/approach Various wave heights and shallow water were used in the experiments and computational process. A 1:40 scaled concrete bridge model was placed in mild beach profile similar to a 24 × 1.5 × 2 m wave flume for the experimental investigation. An Arbitrary Lagrange Euler formulation for the propagation of tsunami solitary and bore waves by an FSI package of LS-DYNA on high-performance computing system was used to evaluate the experimental results. Findings The excellent agreement between experiments and computational simulation is shown in results. The results showed that the fully coupled FSI models could capture the tsunami wave force accurately for all ranges of wave heights and shallow depths. The effects of the overturning moment, horizontal, uplift and impact forces on a pier and deck of the bridge were evaluated in this research. Originality/value Photos and videos captured during the Indian Ocean tsunami in 2004 and the 2011 Japan tsunami showed solitary tsunami waves breaking offshore, along with an extremely turbulent tsunami-induced bore propagating toward shore with significantly higher velocity. Consequently, the outcomes of this current experimental and numerical study are highly relevant to the evaluation of tsunami bore forces on the coastal, over sea or river bridges. These experiments assessed tsunami wave forces on deck pier showing the complete response of the coastal bridge over water.

An Experimental Study of Shallow Water Wave Statistics on Mild Bed Slopes

2011 ◽  
Author(s):  
Vasiliki Katsardi ◽  
Chris Swan
Keyword(s):  
Water Depth ◽  
Measured Data ◽  
Intermediate Water ◽  
Statistical Distributions ◽  
Spectral Bandwidth ◽  
Peak Period ◽  
Wave Statistics ◽  
Wave Heights ◽  
Bed Slope ◽  
Water Depths

This paper describes a new series of laboratory observations, undertaken in a purpose built wave flume, in which a number of scaled simulations of realistic ocean spectra were allowed to evolve over a range of mild bed slopes. The purpose of the study was to examine the distribution of wave heights and its dependence on the local water depth, d, the local bed slope, m, and the nature of the input spectrum; the latter considering variations in the spectral peak period, Tp, the spectral bandwidth and the wave steepness. The results of the study show that for mild bed slopes the statistical distributions of wave heights are effectively independent of both the bed slope and the spectral bandwidth. However, the peak period plays a very significant role in the sense that it alters the effective water depth. Following detailed comparisons with the measured data, the statistical distributions for wave heights in relatively deep water are found to be in reasonable agreement with the Forristall [1] and Glukhovskii [2] distributions. For intermediate water depths, the Battjes & Groenendijk [3] distribution works very well. However, for the shallowest water depths none of the existing distributions provides good agreement with the measured data; all leading to an over-estimate of the largest wave heights.

Development of Deep Water Multicolumn Buoy

2014 ◽  
Author(s):  
Rodrigo A. Barreira ◽  
Vinicius L. Vileti ◽  
Joel S. Sales ◽  
Sergio H. Sphaier ◽  
Paulo de Tarso T. Esperança
Keyword(s):  
Conceptual Design ◽  
Water Depth ◽  
Deep Water ◽  
Model Tests ◽  
Optimization Process ◽  
Life Duration

A new conceptual design of a deepwater MONOBUOY, named DeepWater MultiColumn Buoy (DWMCB), patent PCT/BR2011/000133, was developed by PETROBRAS/CENPES. The DWMCB was designed to be part of an offloading system for a Spread Moored Floating Production Offloading Unit (FPSO). The offloading system principle consists of Oil being exported from the FPSO to a Shutle tanker passing through Offloading Oil Lines (OOLs) that are supported by the DWMCB. The system is designed to operate at a water depth of 2,200 meters, with expected in site life duration of 25 years. The geometry of DWMCB was defined after an optimization process in order to minimize its motions. This paper describes the development of this concept and discusses the results from some design verifications done with the help of a model tests campaign. An equivalent traditional shaped monobuoy was also tested for comparison purposes.

FourStar™ Dry-Tree Semisubmersible Development

2010 ◽  
Author(s):  
Neil Williams ◽  
Steve Leverette ◽  
Sean Bian ◽  
Sean Large ◽  
Peimin Cao
Keyword(s):  
Water Depth ◽  
Model Tests ◽  
Wave Basin

This paper discusses the development of a dry-tree semisubmersible (DTS) platform concept appropriate for deployment in non-hurricane/non-cyclonic environments worldwide, and the verification of the concept through wave basin model tests. An example configuration is presented for an application in 2,100 m water depth offshore Brazil.

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