Characteristics of Hydrodynamics and Generating Output of Offshore Floating Wave Energy Device “Mighty Whale”

2004 ◽  
Author(s):  
Hiroyuki Osawa ◽  
Tsuyoshi Miyazaki ◽  
Shogo Miyajima
Keyword(s):  
Wave Energy ◽  
Wave Power ◽  
Hydrodynamic Behavior ◽  
Extraction Technology ◽  
Energy Device ◽  
Technology Center ◽  
Ocean Wave Energy ◽  
Open Sea ◽  
Theoretical Investigations ◽  
Floating Type

Japan Marine Science and Technology Center (JAMSTEC) has been engaged in research and development of ocean-wave energy extraction technology for many years now. In particular, work began in 1987 an offshore floating type wave power device called “Mighty Whale”. Theoretical investigations and model tests led to an understanding of the hydrodynamic behavior of device, and provided information of constructing for the prototype of Mighty Whale. The open sea tests were started on the 10th of September 1998. Tests were conducted until March 2002. In this paper, firstly, the characteristics of hydrodynamics with “Mighty Whale” have been examined comparing with the results of experiments and calculations approving a numerical method being developed. Secondly, using developed numerical analyze method, the displacements of water level inside air chambers of “Mighty Whale” have been calculated. The generating outputs of “Mighty Whale” have been estimated using these results, the efficiency of primary conversion and the efficiency of secondary conversion of “Mighty Whale” getting through the experiments that had been carried out.

The Open Sea Tests of the Offshore Floating Type Wave Power Device “Mighty Whale”: Performance of the Prototype

2002 ◽  
Author(s):  
Teruhisa Ogata ◽  
Yukihisa Washio ◽  
Hiroyuki Osawa ◽  
Yasushi Tsuritani ◽  
Seiya Yamashita ◽  
...  
Keyword(s):  
Wave Height ◽  
Wave Energy ◽  
Wave Period ◽  
Power Device ◽  
Design Stage ◽  
Wave Power ◽  
Significant Wave ◽  
Type Wave ◽  
Open Sea ◽  
Floating Type

This paper presents the characteristics of wave conditions, wave energy absorption, response of hull-motion and wave height dissipation based on the results of the open sea tests. 0.5–1.0m of significant wave height and 6–7 seconds of significant wave period appear the most predominant, and average wave energy is estimated 4.88kW/m around the test site. Average power output for the test is approximately 6kWh and the maximum total energy efficiency is around 15% that is ranging from 6–7 seconds of significant wave period. Slow drift oscillation of hull was observed motion in surge, sway and yaw and the value of its amplitude almost equal to estimated values in design stage. Then the mean value of transmission coefficient is about 0.8 under 8.0 seconds of significant wave period. We are considering that the results of the tests should be useful for optimum design of an offshore floating type wave power device.

Design of 3D Modeling for the New Wave Power Generation Device and Test

2013 ◽  
Vol 300-301 ◽  
pp. 338-343 ◽  
Author(s):  
Shi Ming Wang ◽  
Ya Nan Wang ◽  
Yin Liu
Keyword(s):  
Wave Energy ◽  
3D Modeling ◽  
Mechanical Energy ◽  
Electric Energy ◽  
Structure Design ◽  
Power Device ◽  
Wave Power ◽  
New Wave ◽  
Ocean Wave Energy ◽  
Power Generation Device

Ocean wave energy is one kind of potential renewable energy that its energy density is far greater than solar energy or wind energy. This paper put forward a new method of using wave turbine to absorb wave energy, then output mechanical energy through mechanical drivers to generator, finally convert to electric energy by generator. Generally, structure design of the wave-wing is very important to the device. It is the important component of the device for absorbing wave energy. For this study, we design the 3D modeling of the new wave power device through SolidWorks software, and generate the wave turbine on proportion of 1:1. We have tested the wave turbine in the pool of the laboratory and obtain the torque and power under certain conditions.

scholarly journals ESTIMATION OF THE WAVE POWER POTENTIAL IN COASTAL REGIONS OF FLORIDA

2018 ◽  
pp. 98
Author(s):  
Cigdem Ozkan ◽  
Talea L. Mayo
Keyword(s):  
Energy Conversion ◽  
Wave Energy ◽  
The United States ◽  
Wave Power ◽  
Renewable Energy Resources ◽  
Wave Energy Conversion ◽  
Coastal Regions ◽  
Ocean Wave Energy ◽  
Wave Power Potential ◽  
Energy Conversion Devices

The state of Florida has an abundance of renewable energy resources. Florida sees sun in an average 60% of its available daylight hours, and has 8,436 miles of coastline, and thus solar and wave energy are two promising alternatives to more conventional energy sources. The Electric Power Research Institute estimates the wave power potential along the Gulf of Mexico coast and East coast of the United States as 60 TWh/year and 160 TWh/year, respectively. One TWh/year can power approximately 93,850 US homes annually, and thus it is likely that ocean wave energy has the potential to greatly contribute to the overall energy supply. This can be acheived by harnessing and converting wave energy into electricity using wave energy conversion devices. However, the feasibility of wave energy conversion must be assessed before such technologies can be employed. As a first step, the amount of available wave power in regions where devices may be deployed should be estimated. In this study, we assess the wave power potential of Florida’s nearshore coastal regions.

scholarly journals Optimal Configurations of Wave Energy Converter Arrays with a Floating Body

2016 ◽  
Vol 23 (s1) ◽  
pp. 71-77 ◽  
Author(s):  
Wanchao Zhang ◽  
Hengxu Liu ◽  
Xuewei Zhang ◽  
Liang Zhang ◽  
Muhammad Aqeel Ashraf
Keyword(s):  
Wave Energy ◽  
Water Environment ◽  
Floating Body ◽  
Energy Device ◽  
Coupled Equations ◽  
Wave Energy Converters ◽  
Ocean Wave Energy ◽  
Floating System ◽  
Interaction Factors ◽  
Optimal Configurations

Abstract An array of floating point-absorbing wave energy converters (WECs) is usually employed for extracting efficiently ocean wave energy. For deep water environment, it is more feasible and convenient to connect the absorbers array with a floating body, such as a semi-submersible bottom-moored disk, whose function is to act as the virtual seabed. In the present work, an array of identical floating symmetrically distributed cylinders in a coaxial moored disk as a wave energy device is proposed The power take-off (PTO) system in the wave energy device is assumed to be composed of a linear/nonlinear damper activated by the buoys heaving motion. Hydrodynamic analysis of the examined floating system is implemented in frequency domain. Hydrodynamic interferences between the oscillating bodies are accounted for in the corresponding coupled equations. The array layouts under the constraint of the disk, incidence wave directions, separating distance between the absorbers and the PTO damping are considered to optimize this kind of WECs. Numerical results with regular waves are presented and discussed for the axisymmetric system utilizing heave mode with these interaction factors, in terms of a specific numbers of cylinders and expected power production.

Elastic Floating Unit With Piezoelectric Device for Harvesting Ocean Wave Energy

2012 ◽  
Author(s):  
Hidemi Mutsuda ◽  
Ryuta Watanabe ◽  
Masato Hirata ◽  
Yasuaki Doi ◽  
Yoshikazu Tanaka
Keyword(s):  
Electric Power ◽  
Wave Energy ◽  
Bluff Body ◽  
Electrical Energy ◽  
Ocean Wave ◽  
Breaking Wave ◽  
Piezoelectric Device ◽  
Ocean Wave Energy ◽  
Floating Type ◽  
Better Than

The purpose of this study is to improve FPED (Flexible PiEzoelectric Device) we have developed. The FPED consisting of piezo-electric polymer film (PVDF) is a way of harvesting electrical energy from ocean power, e.g. tide, current, wave, breaking wave and vortex. We also propose an Elastic Floating unit with HAanging Structures (EFHAS) using FPED. The EFHAS consists of floating unit and hanging unit. In this study, we investigated electric performance of FPED and EFHAS and also modified internal structure of FPED to increase electrical efficiency. As a result, Electric performance is increasing with increasing number of PVDFs laminated in FPED. Multilayer type of FPED can rapidly increase electric efficiency. Electric power can be improved by FPED attached a bluff body with relative density. Electric performance of floating type for floating unit of EFHAS is better than that of submerged type. Distance L/λ = 0.4 between floaters of floating unit is suitable for highly electric performance. In hanging unit of EFHAS, it is possible to increase electric power per unit area with increasing number of stairs. In conclusion, we showed the EFHAS with the FPED could be useful for harvesting ocean wave energy.

Development of Wave Power Generation Technology

2012 ◽  
Vol 512-515 ◽  
pp. 905-909
Author(s):  
Cui Ping Kuang ◽  
Peng Chen Liu ◽  
Yi Pan ◽  
Jie Gu
Keyword(s):  
Power Generation ◽  
Renewable Energy ◽  
Wave Energy ◽  
Wave Power ◽  
Existing Problems ◽  
Ocean Wave Energy ◽  
Power Generation Technology ◽  
Increasing Demand ◽  
Generation Technology ◽  
Wave Power Generation

With the increasing demand of energy, as a clean green renewable energy, ocean wave energy is paid much attention by the countries especially those along coasts. So far, wave power generation technology has experienced decades of development. In this paper, the development and the main wave power generation devices are introduced, moreover, the latest applications of wave energy and existing problems on wave power generation technology are presented.

A New Flapping-Hydrofoil Wave Power Generating Unmanned Ocean Vehicle

2016 ◽  
Author(s):  
Tao Sun ◽  
Jiangbin Zhao ◽  
Xinping Yan ◽  
Pengpeng Xu
Keyword(s):  
Wave Energy ◽  
Energy Harvester ◽  
Clean Energy ◽  
Sea Surface ◽  
Ocean Wave ◽  
Wave Power ◽  
Ocean Science ◽  
Ocean Wave Energy ◽  
Offshore Engineering ◽  
Further Development

To solve the issue of the energy supply for unmanned ocean vehicles, the ocean wave energy as an abundant and widely distributed renewable clean energy, provides a feasible way. This paper proposes a flapping-hydrofoil method applied to unmanned ocean vehicles, harnessing the ocean wave energy to generate power. The structure of the flapping-hydrofoil wave energy harvester is presented, including the internal transmission device and the design of the hydrofoil. Then the operation modes (buoyancy drive and electric drive) and the application prospects (operating on and under the sea surface) of the flapping-hydrofoil wave energy ocean vehicle are also discussed, with the sincere expectations of further development of the ocean science and technology as well as offshore engineering.

The Study on Technology of Ocean Wave Energy Generation

2013 ◽  
Vol 724-725 ◽  
pp. 818-822
Author(s):  
Sheng Ye ◽  
Wei Jun Wang ◽  
Bing Li ◽  
Long Bo Mao
Keyword(s):  
Power Generation ◽  
Wave Energy ◽  
Energy Generation ◽  
Ocean Wave ◽  
Wave Power ◽  
Ocean Wave Energy ◽  
New Energy ◽  
Day By Day ◽  
Generation Technology ◽  
Wave Power Generation

As a source of a clean green renewable new energy, wave power generation is paid much attention by more countries while the decrease of the amount of the energy day by day. The conversion technology in the field of wave energy has tended to mature. Now it is running into commercial exploitation leve1. In this paper, the fundamental principles of ocean wave energy generation technology are presented. The classification and present situation of ocean wave power generation device are introduced. At last, some possible directions and prospects of wave energy generation technology are expatiated.

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