A SCALE MODEL SEDIMENT BYPASSING AND BACK-PASSING SYSTEM ON GALVESTON ISLAND, TEXAS INNOVATIVE TECHNOLOGY FOR REGIONAL SEDIMENT MANAGEMENT

Field deployment for scale model evaluation of an innovative sediment bypassing/back-passing system developing technologies to support present and future sustainable beach nourishment programs and projects on Galveston Island. This is a field scale demonstration project modeling a system designed to harvest beach quality sand using a hybrid, closed system that collects transported bedload material using gravity and natural energies, without any suction component, as sediment is mobilized along the coast through longshore currents and wave energy. The analysis and results of the field deployment will be presented.

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Wave Energy Hyperbaric Device for Electricity Production

Volume 5: Ocean Space Utilization; Polar and Arctic Sciences and Technology; The Robert Dean Symposium on Coastal and Ocean Engineering; Special Symposium on Offshore Renewable Energy ◽

10.1115/omae2007-29743 ◽

2007 ◽

Cited By ~ 7

Author(s):

Segen F. Estefen ◽

Paulo Roberto da Costa ◽

Eliab Ricarte ◽

Marcelo M. Pinheiro

Keyword(s):

Power Generation ◽

Wave Energy ◽

Experimental Results ◽

Electricity Production ◽

Scale Model ◽

Small Scale ◽

Regular Waves ◽

Hyperbaric Chamber ◽

Small Scale Model

Wave energy is a renewable and non-polluting source and its use is being studied in different countries. The paper presents an overview on the harnessing of energy from waves and the activities associated with setting up a plant for extracting energy from waves in Port of Pecem, on the coast of Ceara State, Brazil. The technology employed is based on storing water under pressure in a hyperbaric chamber, from which a controlled jet of water drives a standard turbine. The wave resource at the proposed location is presented in terms of statistics data obtained from previous monitoring. The device components are described and small scale model tested under regular waves representatives of the installation region. Based on the experimental results values of prescribed pressures are identified in order to optimize the power generation.

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Scale and Configuration Effects of an Airchamber on PTO of Oscillating Water Column Type Wave Energy Converters

10.1115/omae2021-62173 ◽

2021 ◽

Author(s):

Tomoki Ikoma ◽

Shota Hirai ◽

Yasuhiro Aida ◽

Koichi Masuda

Keyword(s):

Water Column ◽

Wave Energy ◽

Water Surface ◽

Air Pressure ◽

Scale Model ◽

Linear Potential ◽

Oscillating Water Column ◽

Wave Energy Converters ◽

Air Chamber ◽

Energy Converters

Abstract Wave energy converters (WECs) have been extensively researched. The behaviour of the oscillating water column (OWC) in OWC WECs is extremely complex due to the interaction of waves, air, and turbines. Several problems must be overcome before such WECs can be put to practical use. One problem is that the effect of the difference in scale between a small-scale experimental model and a full-scale model is unclear. In this study, several OWC models with different scales and geometries were used in forced oscillation tests. The wave tank was 7.0 m wide, 24.0 m long, and 1.0 m deep. In the static water experiment, we measured the air pressure and water surface fluctuations in an air chamber. For the experiments, models with a box shape with an open bottom, a manifold shape with an open bottom, and a box shape with a front opening, respectively, were fabricated. Furthermore, 1/1, 1/2, and 1/4 scale models were fabricated for each shape to investigate the effects of scale and shape on the air chamber characteristics. Numerical calculations were carried out by applying linear potential theory and the results were compared with the experimental values. The results confirmed that the air chamber shape and scale affect the air pressure fluctuation and water surface fluctuation inside the OWC system.

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Soil Cleanup by In-Situ Aeration. XVII. Field-Scale Model with Distributed Diffusion

Separation Science and Technology ◽

10.1080/01496399408006939 ◽

1994 ◽

Vol 29 (10) ◽

pp. 1251-1274 ◽

Cited By ~ 6

Author(s):

Céser Gómez-Lahoz ◽

James M. Rodríguez-Maroto ◽

David J. Wilson∗

Keyword(s):

Scale Model ◽

Field Scale ◽

Soil Cleanup

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Experimental Assessment of the Performance of CECO Wave Energy Converter in Irregular Waves

Volume 10: Ocean Renewable Energy ◽

10.1115/omae2018-77686 ◽

2018 ◽

Cited By ~ 1

Author(s):

Claudio A. Rodríguez ◽

F. Taveira-Pinto ◽

P. Rosa-Santos

Keyword(s):

Wave Energy ◽

Transfer Functions ◽

Nonlinear Effects ◽

Model Tests ◽

Experimental Results ◽

Irregular Waves ◽

Scale Model ◽

Experimental Assessment ◽

Simplified Approach ◽

Wave Basin

A new concept of wave energy device (CECO) has been proposed and developed at the Hydraulics, Water Resources and Environment Division of the Faculty of Engineering of the University of Porto (FEUP). In a first stage, the proof of concept was performed through physical model tests at the wave basin (Rosa-Santos et al., 2015). These experimental results demonstrated the feasibility of the concept to harness wave energy and provided a preliminary assessment of its performance. Later, an extensive experimental campaign was conducted with an enhanced 1:20 scale model of CECO under regular and irregular long and short-crested waves (Marinheiro et al., 2015). An electric PTO system with adjustable damping levels was also installed on CECO as a mechanism of quantification of the WEC power. The results of regular waves tests have been used to validate a numerical model to gain insight into different potential configurations of CECO and its performance (López et al., 2017a,b). This paper presents the results and analyses of the model tests in irregular waves. A simplified approach based on spectral analyses of the WEC motions is presented as a means of experimental assessment of the damping level of the PTO mechanism and its effect on the WEC power absorption. Transfer functions are also computed to identify nonlinear effects associated to higher waves and to characterize the range of periods where wave absorption is maximized. Furthermore, based on the comparison of the present experimental results with those corresponding to a linear numerical potential model, some discussions are addressed regarding viscous and other nonlinear effects on CECO performance.

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Development of a New Federally Funded Wind/Wave/Towing Basin to Support the Offshore Renewable Energy Industry

10.5957/attc-2017-0030 ◽

2017 ◽

Author(s):

Alexander Cole ◽

Matthew Fowler ◽

Razieh Zangeneh ◽

Anthony Viselli

Keyword(s):

Renewable Energy ◽

Wave Energy ◽

Wind Wave ◽

Model Testing ◽

Scale Model ◽

Test Facility ◽

Resistance Testing ◽

High Quality ◽

Directional Wave ◽

Wave Maker

This paper presents technical details for a unique newly constructed model testing facility for offshore renewable energy devices and other structures established through federal and state funding. The University of Maine (UMaine) has been an active contributor to research in the field of floating offshore wind turbine (FOWT) design and scale-model testing for the past 6 years. Due to a lack of appropriate test facilities in the United States, UMaine has led multiple 1:50 scale-model tests of FOWT platforms internationally, leading to the motivation to design and build a state-of-the-art test facility at UMaine which includes high-quality wind generation with waves and towing capabilities. In November of 2015, UMaine opened the Alfond Wind/Wave Ocean Engineering Laboratory (W2) at the Advanced Structures and Composites Center. This facility, shown in Figure 1, contains a 30m long x 9m wide x 0-4.5m variable floor depth test basin with a 16-paddle wave maker at one end and a parabolic wave attenuating beach at the other. This basin is unique in that it integrates a rotatable open-jet wind tunnel over the basin that is capable of simulating high-quality wind fields in excess of 10 m/s over a large test area. Since opening, the W2 has provided testing for various scale-model FOWT designs, oil and gas vessels such as a scale-model floating production storage and offloading (FPSO) vessel, and a large number of wave energy conversion (WEC) devices in support of the Department of Energy’s (DOE) Wave Energy Prize. In addition to scalemodel testing, the W2 facility supports a wide range of model construction equipment including a 2.0m x 4.0m x 0.1m tall 3D CNC waterjet, a 3m long x 1.5m wide x 1.4m tall 5-axis CNC router, and an additive manufacturing facility housing a 0.6m x 0.6m x 0.9m 3D printer. To expand the capability of W2, a towing system is currently being designed to operate in conjunction with the multi-directional wave maker, which is shown in Figure 5. This equipment will provide bi-directional towing for a variety of applications. In addition to standard resistance testing, the broad aspect ratio of the basin provides reduced blockage effects while the multi-directional wave maker allows for tow testing a large number of wave environments and headings. The moving floor enables intermediate to shallow water tow tank tests, which are important for capturing the wave kinematics applicable to coastal environments, while the relatively deep water depths support testing of large structures such as tidal turbines and tow-out operations for THE 30th AMERICAN TOWING TANK CONFERENCE WEST BETHESDA, MARYLAND, OCTOBER 2017 2 large offshore structures such as wind and wave floating energy platforms. To test the capabilities of this system, UMaine is constructing a 1:50-scale model of the David Taylor Model Basin (DTMB) 5415 to perform commissioning tests. The towing system is planned to be operational in 2018.

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Physical and numerical modelling of sediment guiding walls in an alpine river

10.5194/egusphere-egu21-14680 ◽

2021 ◽

Author(s):

Jakob Siedersleben ◽

Marco Schuster ◽

Dennis Ties ◽

Benjamin Zwick ◽

Markus Aufleger ◽

...

Keyword(s):

Numerical Model ◽

Numerical Modelling ◽

Power Plants ◽

Sediment Management ◽

Design Flow ◽

Scale Model ◽

Surface Measurement ◽

Management Options ◽

Erosion And Deposition ◽

Alpine River

The presented work is part of the optimization of the sediment management at the hydroelectric powerplants in Reutte/H&#246;fen in Austria. The weirs of the two powerplants are situated at the alpine river Lech, located about 3 km upstream of the Lechaschau gauge (A=1012.2 km&#178;). Totally five sluice gates and a fixed overflow weir are controlling the upstream reservoir, being subjected to high rates of coarse bed load material. In frame of a coupled approach of physical and numerical modelling, different options to (i) avoid/minimize sediment deposition and (ii) allow improved sediment flushing were tested and optimized. Besides a lowering of energy losses (reduced spilling times) the reduction of depositions downstream close to the turbine outlet were considered.The physical model covers the hydropower and weir system of both power plants within a stretch of 400m / 150m using a model scale of 1:25. Investigated situations covered periods of reservoir sedimentation, flushing of the reservoir and typical flood flow situations (e.g. HQ1 and an unsteady HQ5 event). For model parametrization, sediment samples to quantify size distribution were taken in the field. Sediment inputs to the model were realized dynamically and were required (due to scaling effects) to exclude cohesive fractions having a minimum particle size of 0.5 mm. The full-area surface measurement of the river bed was made by means of airborne laser bathymetry and echo sounding.As part of an optimization of the overall sediment management strategy, the focus of the presented research is on the western located runoff power plant H&#246;fen. Via a lateral water intake, a maximum design flow of 15&#160;m&#179;/s is withdrawn causing that the intake structure is subjected to sediment depositions. Within the described scale model (1:25) and a partial scale model (1:15) covering the western side, several management options and configurations of sediment guiding walls were tested. Erosion and deposition as well as the transported material are assessed by 3D laser scanning and permanent monitoring of transported sediment load entering and leaving the scale model.Complementary, a 2D hydro numerical model using a layer based multi fraction approach for sediment transport is set up for an extended area to simulate the morpho-dynamic behavior. The numerical model covers the whole weir system and 750 m of the upstream part of the Lech. The simulations made were realized at nature scale and allowed to mimic the erosion and deposition pattern obtained within the physical modelling for different tested options. Regardless of a chosen guiding wall setup, the results showed that each one is compromise between sediment defense and the effectiveness of the subsequent flushing processes.

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Sustainable sediment management in coastal infrastructures through an innovative technology: preliminary results of the MARINAPLAN PLUS LIFE project

Journal of Soils and Sediments ◽

10.1007/s11368-019-02546-6 ◽

2020 ◽

Vol 20 (6) ◽

pp. 2685-2696 ◽

Cited By ~ 2

Author(s):

Marco Pellegrini ◽

Marco Abbiati ◽

Augusto Bianchini ◽

Marina Antonia Colangelo ◽

Alessandro Guzzini ◽

...

Keyword(s):

Sediment Management ◽

Innovative Technology ◽

Life Project ◽

Preliminary Results

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Numerical and Experimental Investigation on a Moonpool-Buoy Wave Energy Converter

Energies ◽

10.3390/en13092364 ◽

2020 ◽

Vol 13 (9) ◽

pp. 2364 ◽

Cited By ~ 1

Author(s):

Hengxu Liu ◽

Feng Yan ◽

Fengmei Jing ◽

Jingtao Ao ◽

Zhaoliang Han ◽

...

Keyword(s):

Numerical Model ◽

Wave Energy ◽

Wave Energy Converter ◽

Scale Model ◽

Energy Converter ◽

Point Absorber ◽

Motion Responses ◽

Computational Fluid Dynamics Cfd ◽

The Time Domain ◽

Good Agreement

This paper introduces a new point-absorber wave energy converter (WEC) with a moonpool buoy—the moonpool platform wave energy converter (MPWEC). The MPWEC structure includes a cylinder buoy and a moonpool buoy and a Power Take-off (PTO) system, where the relative movement between the cylindrical buoy and the moonpool buoy is exploited by the PTO system to generate energy. A 1:10 scale model was physically tested to validate the numerical model and further prove the feasibility of the proposed system. The motion responses of and the power absorbed by the MPWEC studied in the wave tank experiments were also numerically analyzed, with a potential approach in the frequency domain, and a computational fluid dynamics (CFD) code in the time domain. The good agreement between the experimental and the numerical results showed that the present numerical model is accurate enough, and therefore considering only the heave degree of freedom is acceptable to estimate the motion responses and power absorption. The study shows that the MPWEC optimum power extractions is realized over a range of wave frequencies between 1.7 and 2.5 rad/s.

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