Wave Power Absorption Capability of a Multi-Resonant Double Chamber Oscillating Water Column Device

2014 ◽  
Vol 66 (2) ◽  
Author(s):  
R. Wilbert ◽  
V. Sundar ◽  
S. A. Sannasiraj
Keyword(s):  
Renewable Energy ◽  
Water Column ◽  
Wave Energy ◽  
Renewable Energy Sources ◽  
Absorption Capacity ◽  
Energy Sources ◽  
Wave Power ◽  
Oscillating Water Column ◽  
Power Absorption ◽  
Double Chamber

The reduction of the greenhouse gas emission generated through the usage of fossil fuel has become quite vital forcing us to look for alternative renewable energy sources. Among the renewable energy sources, ocean wave energy looks promising leading to worldwide involvement of researchers in the refinements of a number of the concepts. The conversion of energy available in ocean waves requires an interface device to interact with the kinetic and kinematic phenomena under the waves. These devices are known as wave energy converters (WECS). Among the available WECS oscillating water column (OWC) stands out as one of most promising concept. Though the OWC concept has emerged from laboratory model type to prototype plant, the high cost of production makes it less attractive in commercialism. This necessitates further refinement in the configuration of OWC concept to make it more attractive leading to economically competent. This can be achieved either by improving the efficiency or by integrating it with coastal protective breakwaters, viz., offshore detached breakwaters. The double chamber oscillating water is an innovative concept which can bring forth both efficiency and additional stability once it becomes an integral part of coastal breakwater. This system captures the high magnitude of dynamic pressure as the excitation force for the oscillation inside the OWC. The trajectory of flow pattern can provide additional vertical load which will enhance the stability factor of the breakwater. In this paper the wave power absorption capacity of a 1:20 scale physical model under varying regular wave characteristics is reported. In this insightful study the objective assessment over the hydrodynamic performance reveals the parametric influence over wave power absorption capacity of the device.

Comparison of the performance of oscillating water column devices based on arrangements of water columns

2020 ◽  
Vol 14 (3) ◽  
pp. 7082-7093
Author(s):  
Jahirwan Ut Jasron ◽  
Sudjito Soeparmani ◽  
Lilis Yuliati ◽  
Djarot B. Darmadi
Keyword(s):  
Wave Propagation ◽  
Water Column ◽  
Water Depth ◽  
Graphical Form ◽  
Wave Power ◽  
Oscillating Water Column ◽  
Power Absorption ◽  
Water Columns ◽  
Single Column ◽  
Parallel Arrangement

The hydrodynamic performance of oscillating water column (OWC) depends on the depth of the water, the size of the water column and its arrangement, which affects the oscillation of the water surface in the column. An experimental method was conducted by testing 4 water depths with wave periods of 1-3 s. All data recorded by the sensor is then processed and presented in graphical form. The research focused on analyzing the difference in wave power absorption capabilities of the three geometric types of OWC based on arrangements of water columns. The OWC devices designed as single water column, the double water column in a series arrangement which was perpendicular to the direction of wave propagation, and double water column in which the arrangement of columns was parallel to the direction of wave propagation. This paper discussed several factors affecting the amount of power absorbed by the device. The factors are the ratio of water depth in its relation to wavelength (kh) and the inlet openings ratio (c/h) of the devices. The test results show that if the water depth increases in the range of kh 0.7 to 0.9, then the performance of the double chamber oscillating water column (DCOWC) device is better than the single chamber oscillating water column (SCOWC) device with maximum efficiency for the parallel arrangement 22,4%, series arrangement 20.8% and single column 20.7%. However, when referring to c/h, the maximum energy absorption efficiency for a single column is 27.7%, double column series arrangement is 23.2%, and double column parallel arrangement is 29.5%. Based on the results of the analysis, DCOWC devices in parallel arrangement showed the ability to absorb better wave power in a broader range of wave frequencies. The best wave of power absorption in the three testing models occurred in the wave period T = 1.3 seconds.

Analysis of Wave Energy Sources in the North Atlantic Waters in View of Design Challenges

2016 ◽  
Author(s):  
Jose V. Taboada ◽  
Hirpa G. Lemu
Keyword(s):  
Renewable Energy ◽  
North Atlantic ◽  
Wave Energy ◽  
Energy Resources ◽  
Structural Performance ◽  
Energy Sources ◽  
Wave Power ◽  
Wave Statistics ◽  
Wave Characteristics

This paper describes a wave energy analysis of North Atlantic waters and provides an overview of the available resources. The analysis was conducted using a scatter diagram data combined with wave statistics and empirical parameters given by wave height and periods. Such an overview is instrumental for modelling of wave energy sources, design of wave energy converter (WEC) devices and determination of locations of the devices. Previous survey of wave energy resources widely focused on determination of the reliability on installations of WECs. Though the renewable energy source that can be utilized from the waves is huge, the innovative work in design and development of WECs is insignificant and the available technologies still require further optimization. Furthermore, the wave potential of North Atlantic waters is not sufficiently studied and documented. Closer review of the literature also shows that wave energy conversion technology, compared with other conversion machines of renewable energy sources such as wind energy and solar energy, seems still immature and most of the research and development efforts in this direction are limited in scope. The design of energy converters is also highly dictated by the wave energy resource intensity distribution, which varies from North to South hemisphere. The immaturity of the technology can be attributed to several factors. Since there are a number of uncertainties on the accuracy of wave data, the design, location and installation of WECs face a number of challenges in terms of their service life, structural performance and topological configuration. As a result, collection and assessment of wave characteristics and the wave state conditions data serve as key inputs for development of robust, reliable, operable and affordable wave energy converters. The fact that a number of variables are involved in wave distribution characteristics and the extraction of wave power, treating these variables in the design process imposes immense challenges for the design optimization and hence the optimum energy conversion. The conversion machines are expected to extract as high wave energy as possible while their structural performance is ensured. The study reported in this paper is to analyse wave data over several years of return periods with a detailed validation for wave statistics and wave power. The analysis is intended to contribute in better understanding of the wave characteristics with influencing parameters that can serve as design optimization parameters. A method is proposed to conduct a survey and analysis of the available wave energy resources and the potential at cited locations. The paper concludes that wave energy data accuracy is the baseline for project scoping, coastal and offshore design, and environmental impact assessments.

scholarly journals EVALUATION OF STATIC PRESSURE BEHAVIOR IN AN OSCILLATING WATER COLUMN WAVE ENERGY CONVERTER

2019 ◽  
Vol 18 (1) ◽  
pp. 36
Author(s):  
E. A. Pinto Jr ◽  
M. Das N. Gomes ◽  
L. A. O. Rocha ◽  
E. D. dos Santos ◽  
L. A. Isoldi
Keyword(s):  
Free Surface ◽  
Water Column ◽  
Wave Energy ◽  
Static Pressure ◽  
Sea Water ◽  
Renewable Energy Sources ◽  
Oscillating Water Column ◽  
Flow Acceleration ◽  
Pressure Behavior ◽  
Flow Through

The international scenario of non-renewable resources scarcity coupled with increasing energy demand are incentives for the diversification of the world's energy matrix with a focus on renewable energy sources. Among these sources, energy from sea waves is especially attractive because its global resource is estimated around 2 TW, comparable to the average electrical power consumed worldwide each year. There are currently several technologies proposed for the sea wave energy conversion into electricity. Among them it stands out the Oscillating Water Column (OWC) converter, which basically consists of a hydropneumatic chamber and a turbine duct where a turbine is installed. Its chamber is opened below the sea water free surface while the turbine duct outlet is free to atmosphere. Inside the chamber the water free surface oscillating movement produced by the incident waves causes the air to flow through the turbine duct and to activate the turbine, so the OWC principle of operating can be approximated to a cylinder-piston system. Therefore, one of the methodologies used in the computational modeling to simulate the operating principle of this device is the Piston Methodology, which simplifies the problem analysis considering only the air flow through the OWC converter. Among the phenomena that occur within the OWC device, the static pressure behavior is arguably one of the most important because it is through it that it is possible to estimate the hydropneumatic power and the converter efficiency. Thus, the objective of this work is to evaluate the static pressure behavior within the OWC, using the Piston Methodology, by imposing a monochromatic wave boundary condition in an axisymmetric domain. Among the obtained results it was inferred that the static pressure, in this case, depends directly on the flow acceleration and it is strongly influenced by the vorticity generated in domains with a change of area.

scholarly journals The Study of a Multicriteria Decision Making Model for Wave Power Plant Location Selection in Vietnam

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 650
Author(s):  
Chia-Nan Wang ◽  
Nguyen Thanh ◽  
Chih-Chiang Su
Keyword(s):  
Decision Making ◽  
Renewable Energy ◽  
Wave Energy ◽  
Site Selection ◽  
Energy Sector ◽  
Plant Location ◽  
Electricity Production ◽  
Energy Sources ◽  
Wave Power ◽  
Location Selection

With about a 7% average annual economic growth rate in Vietnam, the demand for electricity production is increasing, and, with more than 3000 km of coastline, the country has great potential for developing wave energy sources to meet such electricity production. This energy source, also known as renewable energy, comes from tides, wind, heat differences, flows, and waves. Both wind and wave energy are considered to have the most potential for energy sources in Vietnam. Just as hydropower projects are controversial due to depleting water resources and regulating floods, nuclear power projects cause safety concerns. To overcome this problem, Vietnamese scientists are considering using abundant wave energy resources for electricity. Nowadays, the ocean energy sector offers many new technologies to help minimize carbon dioxide emissions (CO2) in the living environment. Further, many countries already have wave power plants. In this research, an integrated model, combining the fuzzy analytical network process (FANP) and the technique for order of preference by similarity to ideal solution (TOPSIS), is proposed for wave energy plant location selection. As a result, Con Co (SITE3) is determined the best site for wave energy production. The primary aim of this study is to provide insight into site selection problems for renewable energy investments of Vietnam. The contribution of this research is to propose a fuzzy multiple-criteria decision-making (MCDM) model for site selection in the renewable energy sector. The proposed model also can address different complex problems in location selection; it is also a flexible design model for considering the evaluation criteria; further, it is applicable to site selection of other renewable energies in the world.

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.

scholarly journals Increasing the renewable energy sources absorption capacity of the Macedonian energy system

2013 ◽  
Vol 5 (4) ◽  
pp. 041805 ◽  
Author(s):  
Boris Ćosić ◽  
Nataša Markovska ◽  
Verica Taseska ◽  
Goran Krajačić ◽  
Neven Duić
Keyword(s):  
Renewable Energy ◽  
Renewable Energy Sources ◽  
Energy System ◽  
Absorption Capacity ◽  
Energy Sources
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