Phase Averaged Flow Analysis in an Oscillating Water Column Wave Energy Converter

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Alan Fleming ◽  
Irene Penesis ◽  
Laurie Goldsworthy ◽  
Gregor Macfarlane ◽  
Neil Bose ◽  
...  
Keyword(s):  
Water Column ◽  
Flow Analysis ◽  
Scale Model ◽  
Monochromatic Wave ◽  
Two Dimensional ◽  
Oscillating Water Column ◽  
Energy Converter ◽  
Wave Condition ◽  
Phase Averaging ◽  
Particle Imaging

This paper presents the application of phase averaging to experimental data obtained during scale model testing of a forward facing bent duct oscillating water column (OWC). Phase averaging is applied to both wave probe data and a two-dimensional velocity field at the centerline plane of the OWC model obtained using particle imaging velocimetry (PIV). Results are presented for one monochromatic wave condition. The influence of varied wave frequency is briefly discussed.

Phase Averaged Flow Analysis in an Oscillating Water Column Wave Energy Converter

2011 ◽  
Author(s):  
Alan Fleming ◽  
Irene Penesis ◽  
Laurie Goldsworthy ◽  
Gregor Macfarlane ◽  
Neil Bose ◽  
...  
Keyword(s):  
Experimental Data ◽  
Water Column ◽  
Flow Analysis ◽  
Scale Model ◽  
Monochromatic Wave ◽  
Two Dimensional ◽  
Oscillating Water Column ◽  
Energy Converter ◽  
Wave Condition ◽  
Phase Averaging

This paper presents the application of phase averaging to experimental data obtained during scale model testing of a forward facing bent duct oscillating water column (OWC). Phase averaging is applied to both wave probe data and a two dimensional velocity field at the centreline plane of the OWC model obtained using PIV. Results are presented for one monochromatic wave condition. The influence of varied wave frequency is briefly discussed.

Estimation of Cumulative Output Energy of Oscillating Water Column Wave Energy Converter Considering Power Take Off Damping

2020 ◽  
Author(s):  
Mitsumasa Iino ◽  
Takeaki Miyazaki ◽  
Makoto Iida
Keyword(s):  
Water Column ◽  
Output Power ◽  
Wave Period ◽  
Maximum Efficiency ◽  
Water Tank ◽  
Oscillating Water Column ◽  
Energy Converter ◽  
Air Power ◽  
Wave Condition ◽  
Wide Range

Abstract The objective of this study is to investigate the influence of damping from the PTO device on the cumulative output of the oscillating water column wave energy converter under real sea conditions which encompasses wide range of wave period and height. In this presentation, a time domain dynamic simulation model of OWC motion is developed and validated with water tank test results. Then the model is used to calculate a wide range of wave period and height. Finally, annual cumulative air power output of OWC is calculated with different damping values. In the water tank experiment, a cylindrical oscillating water column with a diameter of 0.3 m and submerged depth of 0.2 m is tested. PTO damping was emulated by using several orifice plates. Since the orifice pressure is proportional to square of flow-rate of the orifice, In the simulation, a model was constructed to solve the dynamic equation of motion assuming water column as a rigid equivalent floating body. Validation showed the model captures the influence of PTO damping as observed in the water tank testing. Using simulation, output air power from real scale OWC was evaluated under wide range of inlet wave period and height. With the output power database from dynamic simulation and frequency of wave height and period at specific sites in Japan (Fukui and Kamaishi), annual cumulative output power is calculated. From the results, it was confirmed that a higher output can be obtained with higher energy in high waves by adopting a damping characteristic that increases the efficiency under a wide wave condition rather than a nozzle characteristic that achieves maximum efficiency in the resonance period. Furthermore, it became clear that the damping that increases the maximum efficiency does not necessarily increase the accumulated energy. When considering operation in real sea condition in the future, it is not always effective to select PTO damping that maximizes the output at specific wave height or period. And it is important to adopt a method that can estimate wide range of wave condition and evaluate the cumulative output power.

scholarly journals Study on Shape Geometry of Floating Oscillating Water Column Wave Energy Converter for Low Heave Wave Condition

2020 ◽  
Vol 70 (2) ◽  
pp. 124-134
Author(s):  
Muhamad Jalani Aiman ◽  
Nur Izzati Ismail ◽  
Mohd Rashdan Saad ◽  
Yasutaka Imai ◽  
Shuichi Nagata ◽  
...  
Keyword(s):  
Water Column ◽  
Wave Energy ◽  
Wave Energy Converter ◽  
Oscillating Water Column ◽  
Energy Converter ◽  
Wave Condition

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

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.

An experimental and numerical analysis of an I-beam attenuator-type, oscillating water column wave energy converter

2015 ◽  
pp. 437-443
Author(s):  
Harry Bingham ◽  
Robert Read ◽  
Frederik Jakobsen ◽  
Morten Simonsen ◽  
Pablo Guillen ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Water Column ◽  
Wave Energy ◽  
Wave Energy Converter ◽  
Oscillating Water Column ◽  
Energy Converter

scholarly journals Geometric Analysis through the Constructal Design of a Sea Wave Energy Converter with Several Coupled Hydropneumatic Chambers Considering the Oscillating Water Column Operating Principle

2021 ◽  
Vol 11 (18) ◽  
pp. 8630
Author(s):  
Yuri Theodoro Barbosa de Lima ◽  
Mateus das Neves Gomes ◽  
Liércio André Isoldi ◽  
Elizaldo Domingues dos Santos ◽  
Giulio Lorenzini ◽  
...  
Keyword(s):  
Water Column ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Wave Energy ◽  
Performance Indicator ◽  
Wave Energy Converter ◽  
Oscillating Water Column ◽  
Energy Converter ◽  
Constructal Design

The work presents a numerical study of a wave energy converter (WEC) device based on the oscillating water column (OWC) operating principle with a variation of one to five coupled chambers. The main objective is to evaluate the influence of the geometry and the number of coupled chambers to maximize the available hydropneumatic power converted in the energy extraction process. The results were analyzed using the data obtained for hydropneumatic power, pressure, mass flow rate, and the calculated performance indicator’s hydropneumatic power. The Constructal Design method associated with the Exhaustive Search optimization method was used to maximize the performance indicator and determine the optimized geometric configurations. The degrees of freedom analyzed were the ratios between the height and length of the hydropneumatic chambers. A wave tank represents the computational domain. The OWC device is positioned inside it, subject to the regular incident waves. Conservation equations of mass and momentum and one equation for the transport of the water volume fraction are solved with the finite volume method (FVM). The multiphase model volume of fluid (VOF) is used to tackle the water–air mixture. The analysis of the results took place by evaluating the performance indicator in each chamber separately and determining the accumulated power, which represents the sum of all the powers calculated in all chambers. The turbine was ignored, i.e., only the duct without it was analyzed. It was found that, among the cases examined, the device with five coupled chambers converts more energy than others and that there is an inflection point in the performance indicator, hydropneumatic power, as the value of the degree of freedom increases, characterizing a decrease in the value of the performance indicator. With the results of the hydropneumatic power, pressure, and mass flow rate, it was possible to determine a range of geometry values that maximizes the energy conversion, taking into account the cases of one to five coupled chambers and the individual influence of each one.

NUMERICAL ANALYSIS OF A SAVONIUS TURBINE INSERTED IN OSCILLATING WATER COLUMN WAVE ENERGY CONVERTER

2021 ◽  
Author(s):  
Andrei Santos ◽  
Filipe Branco Teixeira ◽  
Liércio Isoldi ◽  
jeferson Avila Souza ◽  
Mateus das Neves Gomes ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Water Column ◽  
Wave Energy ◽  
Wave Energy Converter ◽  
Oscillating Water Column ◽  
Energy Converter
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