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.

DISPERSANT TESTS IN A WAVE BASIN

1985 ◽  
Vol 1985 (1) ◽  
pp. 463-469 ◽  
Author(s):  
M. R. MacNeill ◽  
R. H. Goodman ◽  
J. B. Bodeux ◽  
K. E. Corry ◽  
B. A. Paddison
Keyword(s):  
Water Column ◽  
Field Experiments ◽  
Oil Spills ◽  
Low Energy ◽  
Water Emulsion ◽  
Oil In Water ◽  
Wave Basin ◽  
Wave Generator ◽  
Oil In Water Emulsion ◽  
And Control

ABSTRACT Using dispersants to mitigate oil spills has remained controversial, despite considerable testing, in both the laboratory and the field. One of the major concerns, which has not been satisfactorily resolved, is how effective various dispersants are on different oils over a range of environmental conditions. Laboratory experiments cannot accurately simulate the real world, while field experiments are difficult to monitor and control. To eliminate some of the problems previously encountered when testing dispersants, an experiment was conducted in a large (approximately 30 m × 55 m × 2.5 m deep) outdoor wave test basin. The main objective of the experiment was to test the action of Corexit 9527 on unweathered Issungnak crude oil in low energy, nonbreaking waves. Eight tests were conducted, four on control oil slicks and four on treated slicks. The oil was contained in a 4.6 m diameter boom with a 1.85 m deep skirt. The boom was moored at one end of the test basin 6 m from a wave generator, which could generate waves up to 0.4 m high. At the opposite (shallow) end of the wave basin, a gravel beach absorbed the energy of the waves. For each test, the wave generator was run for about 4 hours, with a constant wave height (set from 10 to 28 cm) and period (1.6 s). During this time, water samples were drawn at regular intervals from various depths for measuring oil concentrations in the water column. The data indicated that, in 10 and 20 cm nonbreaking waves, dispersion of oil into the water column from an untreated oil slick was negligible. During all the experiments for treated slicks, concentrations of oil in the boom were dramatically higher than for untreated slicks. Even in quiescent conditions, concentrations as high as 4 ppm were observed at 50 cm after 24 hours under a treated slick. Concentrations of up to 60 ppm were observed at 50 cm in the water column in 10 cm waves. Investigations of oil drop size showed that under the treated slicks the oil droplet diameters ranged from 1 µm to 8 µm diameter. Overall, the results showed that, even in low energy waves, there was a significant increase in dispersion from a surface slick of unweathered Issungnak oil when it was treated with Corexit 9527, and the oil in water emulsion formed was more stable than that from an untreated slick.

Simulation of Hurricane Seas in a Multidirectional Wave Basin

1991 ◽  
Vol 113 (3) ◽  
pp. 219-227 ◽  
Author(s):  
A. Cornett ◽  
M. D. Miles
Keyword(s):  
Ocean Waves ◽  
Entropy Method ◽  
Wave Spectra ◽  
Single Wave ◽  
Wave Condition ◽  
Wave Basin ◽  
Wide Range ◽  
Directional Wave ◽  
Wave Conditions ◽  
Multidirectional Wave

This paper describes the generation and verification of four realistic sea states in a multidirectional wave basin, each representing a different storm wave condition in the Gulf of Mexico. In all cases, the degree of wave spreading and the mean direction of wave propagation are strongly dependent on frequency. Two of these sea states represent generic design wave conditions typical of hurricanes and winter storms and are defined by JONSWAP wave spectra and parametric spreading functions. Two additional sea states, representing the specific wave activity during hurricanes Betsy and Carmen, are defined by tabulated hindcast estimates of the directional wave energy spectrum. The Maximum Entropy Method (MEM) of directional wave analysis paired with a single-wave probe/ bi-directional current meter sensor is found to be the most satisfactory method to measure multidirectional seas in a wave basin over a wide range of wave conditions. The accuracy of the wave generation and analysis process is verified using residual directional spectra and numerically synthesized signals to supplement those measured in the basin. Reasons for discrepancy between the measured and target directional wave spectra are explored. By attempting to reproduce such challenging sea states, much has been learned about the limitations of simulating real ocean waves in a multidirectional wave basin, and about techniques which can be used to minimize the associated distortions to the directional spectrum.

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.

Optimum Design and Control of Self-Supported Wave Energy Systems

1982 ◽  
Vol 104 (3) ◽  
pp. 247-256
Author(s):  
A. Abuelnaga ◽  
A. Seireg
Keyword(s):  
Optimum Design ◽  
Conversion Efficiency ◽  
Wave Energy ◽  
Energy Systems ◽  
Significant Loss ◽  
Mass System ◽  
Wave Generator ◽  
Single Mass ◽  
And Control

In a previous paper by the authors [1] a procedure is given for the optimum design of single mass, anchored wave energy generators. The anchoring problem is generally regarded as one of the major obstacles of developing practical systems due to the high cost of implementation. This paper presents a procedure for the design of supporting platforms for wave generators which are essentially self-positioned and require minimum anchoring. The optimum design and control for such systems is given for a selected ocean condition. The study shows that an unanchored platform in an optimally designed two-mass system can provide appropriate support for the wave generator without any significant loss of conversion efficiency.

OIL SPILL STRATEGY IN THE FEDERAL REPUBLIC OF GERMANY: NEW TECHNICAL DEVELOPMENTS IN MECHANICAL SPILL RESPONSE

1989 ◽  
Vol 1989 (1) ◽  
pp. 265-271
Author(s):  
Klaus Schroh
Keyword(s):  
Federal Republic ◽  
Oil Spill ◽  
Oil Recovery ◽  
Wadden Sea ◽  
Oil Spills ◽  
Oil Pollution ◽  
Federal Republic Of Germany ◽  
Technical Developments ◽  
Wave Heights ◽  
And Control

ABSTRACT Prevention and control of oil spills in the Federal Republic of Germany are based on an agreement between the federal government and the four coastal states. Comprehensive procurement and reconstruction programs for oil pollution personnel and equipment are realized and finalized within two years. The Federal Minister for Research and Technology contributed substantially toward using advanced oil spill response techniques at sea and for shoreline cleanup. Since the particular ecological conditions of the Wadden Sea on the German coastline greatly limit dispersant application, main emphasis was given to developing recovery systems meeting the following requirements:An extended scope of mechanical application at sea, for wave heights exceeding 1.2 m (4 feet)New types of recovery vessels with multiple functions, like bunkering services and floating reception facilitiesOil recovery with self-driven vessels for shallow waters close to the coastline and embankmentsDesign of an amphibious chain-driven vehicle for oil recovery in Wadden Sea areas. With the integration of these new types of oil recovery vessels or systems the German recovery fleet now consists of 6 high-sea-going vessels and 14 recovery vessel devices for shoreline cleanup.

A 600 KV. ION ACCELERATOR

1948 ◽  
Vol 26f (10) ◽  
pp. 419-425
Author(s):  
J. V. Jelley ◽  
E. B. Paul
Keyword(s):  
Research Council ◽  
Ion Beam ◽  
National Research Council ◽  
Ion Source ◽  
Ion Acceleration ◽  
Source Power ◽  
Atomic Ions ◽  
Ion Accelerator ◽  
And Control

The 600 kv. ion acceleration equipment that has been developed at the Ottawa Laboratory of the National Research Council is described. Details of ion source power column, and control gear are given. Using hydrogen a total ion beam of 250 to 300 μa. was obtained, of which about 80% was atomic ions.

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 Analysis and Scaled High Resolution Tank Testing of a Novel Wave Energy Converter

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Ken Rhinefrank ◽  
Al Schacher ◽  
Joe Prudell ◽  
Joao Cruz ◽  
Chad Stillinger ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Wave Energy ◽  
Wave Energy Converter ◽  
Numerical Code ◽  
Scale Model ◽  
Energy Converter ◽  
Modeling Tools ◽  
Wave Basin ◽  
Wave Research ◽  
Multidirectional Wave

This paper presents a novel point absorber wave energy converter (WEC), developed by Columbia Power Technologies (COLUMBIA POWER), in addition to the related numerical analysis and scaled wave tank testing. Three hydrodynamic modeling tools are employed to evaluate the performance of the WEC, including WAMIT, GL Garrad Hassan's GH WaveDyn, and OrcaFlex. GH WaveDyn is a specialized numerical code being developed specifically for the wave energy industry. Performance and mooring estimates at full scale are evaluated and optimized, followed by the development of a 1:33 scale physical model. The physical tests of the 1:33 scale model WEC were conducted at the multidirectional wave basin of Oregon State University's O.H. Hinsdale Wave Research Laboratory, in conjunction with the Northwest National Marine Renewable Energy Center (NNMREC). This paper concludes with an overview of the next steps for the modeling program and future experimental test plans.

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