The progress in wave energy conversion in Europe during the past ten years is reviewed and current activities and initiatives in the wave energy sector at National and Union level are described. Other important activities worldwide are summarized. The technical and econ

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Wave energy in Europe: current status and perspectives

Oscillating-water-column wave energy converters and air turbines: A review

One of the most abundant energy sources exists in this world is the ocean wave energy. By far, it has shown to be the most clean, renewable, predicted energy and has raised the potential to compete with the current use of non-renewable energy sources. Recent research conducted on wave energy invention has opened a new dimension to slowly reduce the dependency on fossil fuel by introducing new technology on the renewable world but relatively lacking in economical aspect. This review brings the latest status on integration of wave energy device with other marine facilities, which is the breakwater structure that may possibly aid to cost sharing. Most researches done on this field highlighted countries experiencing rough sea condition and focused less on countries with medium wave condition as faced by the Asian continent. The potential for energy extraction and wave dissipation for medium wave condition will be discussed in this review by considering several aspects including reliability, effectiveness and performance. Finally, this review shows that the integration opens up a new dimension to acknowledge the technology harnessing ocean wave, especially for the Asian countries experiencing medium wave condition.

Wave energy device and breakwater integration: A review

"Comprehensive Renewable Energy" is the only multi-volume reference work of its type at a time when renewable energy sources are seen increasingly as realistic alternatives to fossil fuels. As the majority of information published for the target audience is currently available via a wide range of journals, seeking relevant information (be that experimental, theoretical, and computational aspects of either a fundamental or applied nature) can be a time-consuming and complicated process. "Comprehensive Renewable Energy" is arranged according to the most important themes in the field (photovoltaic technology; wind energy technology; fuel cells and hydrogen technology; biomass and biofuels production; hydropower applications; solar thermal systems: components and applications; geothermal energy; ocean energy), and as such users can feel confident that they will find all the relevant information in one place, with helpful cross-referencing between and within all the subject areas, to broaden their understanding and deepen their knowledge. It is an invaluable resource for teaching as well as in research. Available online via SciVerse ScienceDirect and in print. Editor-in Chief, Professor Ali Sayigh (Director General of WREN (World Renewable Energy Network) and Congress Chairman of WREC (World Renewable Energy Congress, UK) has assembled an impressive, world-class team of Volume Editors and Contributing Authors. Each chapter has been painstakingly reviewed and checked for consistent high quality. The result is an authoritative overview which ties the literature together and provides the user with a reliable background information and citation resource. The field of renewable energy counts several journals that are directly and indirectly concerned with the field. There is no reference work that encompasses the entire field and unites the different areas of research through deep foundational reviews. "Comprehensive Renewable Energy" fills this vacuum, and can be considered the definitive work for this subject area. It will help users apply context to the diverse journal literature offering and aid them in identifying areas for further research. Research into renewable energy is spread across a number of different disciplines and subject areas. These areas do not always share a unique identifying factor or subject themselves to clear and concise definitions. This work unites the different areas of research and allows users, regardless of their background, to navigate through the most essential concepts with ease, saving them time and vastly improving their understanding. There are more than 1000 references from books, journals and the internet within the eight volumes. It is full of color charts, illustrations and photographs of real projects and research results from around the world. The only reference work available that encompasses the entire field of renewable energy and unites the different areas of research through deep foundational reviews. Allows readers, regardless of their background, to navigate through the most essential concepts with ease, saving them time and vastly improving their understanding.

Comprehensive Renewable Energy

https://pure.hw.ac.uk/ws/files/22846703/Ning_Zou_OWC_HOBEM_Energy_Accepted_manuscript_Energy2015.pdf

Investigation of hydrodynamic performance of an OWC (oscillating water column) wave energy device using a fully nonlinear HOBEM (higher-order boundary element method)

The wave power generating system using the Wells turbine is installed in the breakwater in Sakata port, Japan, and consists of the air chamber, turbine, generator and safety devices. The purposes of this paper are to reveal the characteristics of each component in this system with the experimental data in the real sea, and to evaluate the accuracy of numerical models used in the simulation. The performance of Wells turbine is examined in detail for the unsteady and full-scale condition, comparing the data of the 1/4 scale model with the steady full-scale one. As for the motion of water in the air chamber, the eigenfunction expansion method is introduced, and the wave height measured 275m away from the chamber is employed for the input of the simulation. It is found that the performance of the system for the wave can be evaluated accurately with the steady-characteristics of the turbine, in the condition that the stall does not happen on the rotor. The angle of attack for the stall depends on the wave characteristics such as the magnitude of unsteadiness, requiring many trials to get the stall angle used by the calculations. The error of the simulation for the total system is finally predicted to be less than 20% when the wave comes within the region of about 20 degree deviation angle.

Performance of Wave Power Generating System Installed In Breakwater At Sakata Port In Japan

Guide vanes are installed in the Wells turbine in order to improve the performance such as efficiency, self-rotating characteristics and off-design one with stall. This paper tries to make clear the roles of guide vanes for turbine systems with the simple momentum theory. It is found that the upstream guide vanes are more effective for the efficiency than the downstream guide vanes. The guide vanes are designed by using experimental data from the rotor without guide vane and potential flow calculation around guide vane. Experimental investigations on the effect of the guide vanes for the performance of Wells turbine are carried out and rearranged to confirm the momentum theory proposed in this paper.

Guide Vanes Effect of Wells Turbine For Wave Power Generator

The Wells turbine rotor consists of several symmetric airfoil blades arranged around a central hub, and the stagger angle is 90 degrees. These characteristics simplify the total construction of OWC type wave energy converters. Although the Wells turbine is simple, the turbine produces a complicated flow field due to the peculiar arrangement of blades, which can rotate in the same direction irrespective of the oscillating airflow. In order to understand these flows, flow visualization is carried out with an oil-film method in the water tunnel. This research aims to analyze the mechanism of the 3-D flows around the turbine with the flow visualization. The flow visualization explained the influence of attack angle, the difference between fan-shaped and rectangular wings, and the sweep angle.

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Influence of Blade Profiles on Flow around Wells Turbine

A floating type backward-bent duct buoy (BBDB) is a wave energy conversion device with an oscillating water column (OWC) at the front side. The device captures the wave energy using the heaving, the pitching, the surging motion of BBDB, and the heaving motion of OWC. Investigations are carried out to find more reasonable devices than the traditional OWC type floating device. An eigenfunction expansion method is introduced for analyzing the BBDB with OWC. It is confirmed that these solutions give good agreement with several experimental results in this paper. It is shown in a design method how to make BBDB match the turbine characteristics. This feature is being able to select the optimum profile of the turbine and the BBDB individually from each characteristic before comprehensive evaluation of the BBDB and the turbine in the design. After grasping the element characteristics, which are appropriate for the wave energy conversion system, the synthetic design method is built. The BBDB size and the turbine diameter are determined by considering the cost corresponding to the smallest size under the same output. In this way, we can obtain the optimal profiles considering the construction cost including the turbines.

Numerical Investigation of 2D Optimal Profile of Backward-Bent Duct Type Wave Energy Converter

In order to find out the influence of solidity on Wells turbine, experiments were carried out in series with fan-shaped wings which had a constant solidity from hub to tip. The findings are that the most efficient solidity is about 0.6, and that as the solidity increases, the operating range of negative torque becomes smaller, though all turbines cannot start by themselves in a uniform flow. Owing to calculations which consider the effects of sine wave input and the inertia of turbine, some turbines are shown to be self-started. Furthermore, with an appropriate flow rate control, other turbines can also rotate in a high-speed condition theoretically.

Masami Suzuki

Papers

Performance of Wave Power Generating System Installed In Breakwater At Sakata Port In Japan

Guide Vanes Effect of Wells Turbine For Wave Power Generator

Influence of Blade Profiles on Flow around Wells Turbine

Numerical Investigation of 2D Optimal Profile of Backward-Bent Duct Type Wave Energy Converter

Fundamental Studies on Wells Turbine for Wave Power Generator ; 1st Report, The Effect of Solidity, and Self-Starting