scholarly journals Performance Assessment of a Hybrid Wave Energy Converter Integrated into a Harbor Breakwater

Energies ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 236 ◽  
Author(s):  
Tomás Cabral ◽  
Daniel Clemente ◽  
Paulo Rosa-Santos ◽  
Francisco Taveira-Pinto ◽  
Tiago Morais ◽  
...  
Keyword(s):  
Wave Energy ◽  
Experimental Tests ◽  
Wave Power ◽  
Oscillating Water Column ◽  
Hybrid Wave ◽  
Energy Converter ◽  
Ansys Fluent ◽  
Wave Energy Converters ◽  
Model Study ◽  
Geometrical Scale

Seaports are highly energy demanding infrastructures and are exposed to wave energy, which is an abundant resource and largely unexploited. As a result, there has been a rising interest in integrating wave energy converters (WEC) into the breakwaters of seaports. The present work analyzes the performance of an innovative hybrid WEC module combining an oscillating water column (OWC) and an overtopping device (OWEC) integrated into a rubble mound breakwater, based on results of a physical model study carried out at a geometrical scale of 1:50. Before the experimental tests, the device’s performance was numerically optimized using ANSYS Fluent and WOPSim v3.11. The wave power captured by the hybrid WEC was calculated and the performance of the two harvesting principles discussed. It was demonstrated that hybridization could lead to systems with higher efficiencies than its individual components, for a broader range of wave conditions. The chosen concepts were found to complement each other: the OWEC was more efficient for the lower wave periods tested and the OWC for the higher. Consequently, the power production of the hybrid WEC was found to be less dependent on the wave’s characteristics.

On the Array of Wave Energy Converters: The Case of the Coaxial-Duct OWC

2018 ◽  
Author(s):  
J. C. C. Portillo ◽  
J. C. C. Henriques ◽  
R. P. F. Gomes ◽  
L. M. C. Gato ◽  
A. F. O. Falcão
Keyword(s):  
Wave Energy ◽  
Oscillating Water Column ◽  
Economic Activities ◽  
Energy Converter ◽  
Diverse Range ◽  
Wave Energy Converters ◽  
Large Size ◽  
New Findings ◽  
Water Columns ◽  
Oscillating Water Columns

This work focuses on the initial performance assessment of an array of coaxial-duct (CD) oscillating-water-columns (owc’s) with potential to be used as multipurpose platform for the creation of value in a diverse range of offshore economic activities. The coaxial-duct owc (CD-owc) is an axisymmetric oscillating-water-column wave energy converter that has been studied for both small-size and large-size applications. This work focuses on buoys of 12 meter diameter distributed in an array of five devices, rigidly attached to each other, to form a cluster of owc’s. The objective of the study is to assess the performance of the array with this configuration and estimate the effect of parameters such as distance between devices, various modes of movements, and other constraints on the overall power output of the array. Results of different cases are compared to the performance of an isolated device to determine the interference effect of other devices. Some results validate previous research conclusions and new findings on the behavior coaxial-duct owc are presented.

Basic Characteristics of the Primary Conversion of an OWC Type WEC Installed on a Wave Dissipating Double-Caisson

2018 ◽  
Author(s):  
Tomoki Ikoma ◽  
Koichi Masuda ◽  
Hiroaki Eto ◽  
Shogo Shibuya
Keyword(s):  
Wave Height ◽  
Basic Property ◽  
Wave Energy ◽  
Wave Power ◽  
Oscillating Water Column ◽  
Type Wave ◽  
Wave Energy Converters ◽  
The World ◽  
Fixed Type ◽  
Basic Characteristics

Several types of oscillating water column (OWC) type wave energy converters (WECs) are researched and developed in the world. They are floating types and fixed types. In case of a fixed type, wave dissipating caissons could be replaced to WECs of an OWC type. On OWC types, installation of the projecting-walls (PWs) is useful in order to improve PTO performance. In this study, it was considered that a double dissipating caisson was used as an OWC type WEC with PWs. A front caisson of the double caisson seems the area surrounded by PWs and a back caisson can be seen as an OWC. The paper studied basic property of the primary conversion from wave power to power of air from model tests in a wave tank. As a result, wave height strongly effects on behaviours of OWC motion as well as air pressure. Finally, the primary conversion was affected by wave height. Besides, the concept of use of a double caisson was useful from the primary conversion over 80 % evaluated using test data.

scholarly journals TURBINE−CHAMBER COUPLING IN AN OWC WAVE ENERGY CONVERTER

2012 ◽  
Vol 1 (33) ◽  
pp. 2 ◽  
Author(s):  
Ivan Lopez ◽  
Gregorio Iglesias ◽  
Mario Lopez ◽  
Francisco Castro ◽  
Miguel Ángel Rodríguez
Keyword(s):  
Numerical Modeling ◽  
Water Column ◽  
Wave Energy ◽  
Wave Power ◽  
Optimum Level ◽  
Oscillating Water Column ◽  
Wave Energy Conversion ◽  
Energy Converter ◽  
Air Turbine ◽  
Pneumatic Power

Oscillating Water Column (OWC) systems are one of the most popular technologies for wave energy conversion. Their main elements are the chamber with the water column and the air turbine. When studying the performance of an OWC system both elements should be considered together, for they are effectively coupled: the damping exerted by the air turbine affects the efficiency of the conversion from wave power to pneumatic power in the OWC chamber, which in turn affects the air flow driving the turbine. The optimum level of damping is that which maximizes the efficiency of the conversion from wave to pneumatic power. In this work the turbine-chamber coupling is studied through a combination of physical and numerical modeling.

The Principle, Review and Prospect of Wave Energy Converter

2011 ◽  
Vol 347-353 ◽  
pp. 3744-3749
Author(s):  
Yu Jiong Gu ◽  
Li Jun Zhao ◽  
Jing Hua Huang ◽  
Bing Bing Wang
Keyword(s):  
Wave Energy ◽  
Wave Energy Converter ◽  
Wave Power ◽  
Power Development ◽  
Energy Converter ◽  
Basic Principles ◽  
Technology Application ◽  
Energy And Environment ◽  
Point Absorber ◽  
Wave Energy Converters

Abstract: Being confronted with the severity of the energy and environment problems, the world attaches more and more importance to the potential of wave energy. Based on the necessity and feasibility of wave power development, the basic principles of wave energy converter are in this paper firstly. Then some kinds of WEC’s principle, merits and drawbacks, technology application are reviewed, such as OWC, raft, Tapchan, point absorber, Salter, pendulum. After that, wave energy developing conditions in some typical countries are recommended. After reviewing the features of various wave energy converters and WEC application examples in some countries, prospect and a few problems in wave energy utilizing are stated briefly.

scholarly journals Study on an Oscillating Water Column Wave Power Converter Installed in an Offshore Jacket Foundation for Wind-Turbine System Part I: Open Sea Wave Energy Converting Efficiency

2021 ◽  
Vol 9 (2) ◽  
pp. 133
Author(s):  
Hsien Hua Lee ◽  
Guan-Fu Chen ◽  
Hsiang-Yu Hsieh
Keyword(s):  
Wind Turbine ◽  
Water Column ◽  
Wind Power ◽  
Wave Energy ◽  
Wave Energy Converter ◽  
Offshore Wind ◽  
Wave Power ◽  
Oscillating Water Column ◽  
Energy Converter ◽  
Wind Turbine System

This study is focused on the wave energy converter of an oscillating water column (OWC) system that is integrated with a jacket type infrastructure applied for an offshore wind turbine system. In this way, electricity generation by both wind power and wave power can be conducted simultaneously to maximize the utilization of sustainable energy. A numerical analysis was performed in this research to model and simulate the airflow response and evaluate the converting efficiency of wave energy from an OWC system integrated with an offshore template structural system. The performance of the system including the generating airflow velocity, air-pressure in the chamber, generating power and then the converting efficiency of power from waves are all analyzed and discussed in terms of the variations of the OWC system’s geometrical parameters. The parameters under consideration include the exhale orifice-area of airflow, gate-openings of inflow water and the submerged chamber depth. It is found that from the analytical results the performance of the OWC wave energy converter is influenced by the dimensional parameters along with the design conditions of the local environment. After a careful design based on the in-situ conditions including water depth and wave parameters, an open OWC system can be successfully applied to the template structure of offshore wind power infrastructure as a secondary generating system for the multi-purpose utilization of the structure.

scholarly journals Total wave power absorption by a multi-float wave energy converter and a semi-submersible wind platform with a fast far field model for arrays

2021 ◽  
Author(s):  
Peter Stansby ◽  
Efrain Carpintero Moreno ◽  
Sam Draycott ◽  
Tim Stallard
Keyword(s):  
Wind Turbine ◽  
Wave Energy ◽  
Radiation Damping ◽  
Wave Energy Converter ◽  
Wave Power ◽  
Far Field ◽  
Energy Converter ◽  
Power Absorption ◽  
Wave Energy Converters ◽  
Total Wave

AbstractWave energy converters absorb wave power by mechanical damping for conversion into electricity and multi-float systems may have high capture widths. The kinetic energy of the floats causes waves to be radiated, generating radiation damping. The total wave power absorbed is thus due to mechanical and radiation damping. A floating offshore wind turbine platform also responds dynamically and damping plates are generally employed on semi-submersible configurations to reduce motion, generating substantial drag which absorbs additional wave power. Total wave power absorption is analysed here by linear wave diffraction–radiation–drag models for a multi-float wave energy converter and an idealised wind turbine platform, with response and mechanical power in the wave energy case compared with wave basin experiments, including some directional spread wave cases, and accelerations compared in the wind platform case. The total power absorption defined by capture width is input into a far field array model with directional wave spreading. Wave power transmission due a typical wind turbine array is only reduced slightly (less than 5% for a 10 × 10 platform array) but may be reduced significantly by rows of wave energy converters (by up to about 50%).

Improvement of Performance of Wave Power Conversion Due to the Projecting Walls for Oscillating Water Column Type Wave Energy Converter

2016 ◽  
Vol 138 (2) ◽  
Author(s):  
Tomoki Ikoma ◽  
Koichi Masuda ◽  
Hikaru Omori ◽  
Hiroyuki Osawa ◽  
Hisaaki Maeda
Keyword(s):  
Water Column ◽  
Wave Energy ◽  
Prediction Method ◽  
Past Research ◽  
Wave Energy Converter ◽  
Air Pressure ◽  
Wave Power ◽  
Linear Potential ◽  
Oscillating Water Column ◽  
Energy Converter

This paper describes a method to improve the performance of primary conversion of wave power takeoff. The wave energy converter (WEC) used here was of oscillating water column (OWC) type. This method for improvement has been already proposed in past research and its usefulness has been confirmed. It involves projecting walls (PWs) being attached to the front of the inlet–outlet of the OWC. The prediction method of hydrodynamic behaviors for the OWC type WEC with PWs installed is explained in this paper. The boundary element method with the Green's function is applied, and influence of air pressure and free surface within every air-chamber was directly taken into consideration in the prediction method based on linear potential theory. Validity of the prediction method was proved by comparing the results with the results of model experiments. Series calculations are performed with the prediction method. Behaviors of air pressure, water elevation, and the efficiency of primary conversion of wave power were investigated. From the calculations, length of the PWs was shown to affect the efficiency of primary conversion. It was possible to equip the PWs so as to enable improvements in oblique waves to beam sea conditions as well as in the head sea conditions. This paper examined not only the PWs but also the application and effects of the end walls (EWs) with the slit. The EWs were very useful to improve the efficiency.

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