Cascade wind turbines for the oscillating water column wave energy device: Part 1

1996 ◽  
Vol 9 (1-4) ◽  
pp. 1219-1222
Author(s):  
Kunal Ghosh
Keyword(s):  
Water Column ◽  
Wind Turbines ◽  
Wave Energy ◽  
Oscillating Water Column ◽  
Energy Device

On the Efficiency and Transmission Characteristics of a 1:20 Model Fixed Wave Energy Device

2003 ◽  
Author(s):  
E. Vijayakrishna Rapaka ◽  
S. Neelamani ◽  
R. Natarajan
Keyword(s):  
Wave Propagation ◽  
Water Column ◽  
Water Depth ◽  
Wave Energy ◽  
Oscillating Water Column ◽  
Wave Energy Conversion ◽  
Transmission Characteristics ◽  
Energy Device ◽  
Average Value ◽  
Model Study

Wave transmission and pneumatic efficiency of an oscillating water column (OWC) type wave energy device resting on group of piles is investigated using physical model study. The caisson blocks 45% of the water depth. The co-efficient of transmission of the device varies from 0.1 to 0.4 for B/L range of 0.1 to 0.7, where ‘B’ is the width of the caisson in the direction of wave propagation and ‘L’ is the wavelength. The pneumatic efficiency varies from 20% to 50% with an average value of 0.35. The results of the present study can be used in the design of OWC caisson used for both wave energy conversion and breakwater in deeper water.

scholarly journals Geometrical investigation of a U-shaped oscillating water column wave energy device

2020 ◽  
Vol 97 ◽  
pp. 102105
Author(s):  
De-zhi Ning ◽  
Bao-ming Guo ◽  
Rong-quan Wang ◽  
Thomas Vyzikas ◽  
Deborah Greaves
Keyword(s):  
Water Column ◽  
Wave Energy ◽  
Oscillating Water Column ◽  
Energy Device ◽  
Geometrical Investigation

A Tethered Multiple Oscillating Water Column Wave Energy Device: From Concept to Deployment

2002 ◽  
Author(s):  
John Chudley ◽  
Y. Ming Dai ◽  
Fraser Johnson
Keyword(s):  
Engineering Design ◽  
Water Column ◽  
Wave Energy ◽  
Phase Locking ◽  
Wave Climate ◽  
Oscillating Water Column ◽  
Impulse Turbine ◽  
Energy Device ◽  
Local Wave ◽  
The Individual

This paper discusses the research and design methodology employed in the development of a tethered Multiple Oscillating Water Column (MOWC) wave energy device – from concept to deployment. The fundamental aim of the project was the design and deployment of a scaled floating MOWC wave energy device capable of generating physical data from sea trials. The MOWC collector component incorporated oscillating columns connected to a self-rectifying impulse turbine via individual settling chambers. The device has a water draught of 12m and an air draught of 3m. It is of cylindrical design with an overall diameter of 4.4m, displacing 10t The present unit is rated to at 5 kW power output through restrictions of the internal airflows. Research indicates that a full-scale unit 5 times bigger than the scaled device would be capable of generating 500 – 750 kW in a moderately rough sea. The paper addresses the complex problems associated with floating MOWC devices and suggests methods to enable accurate modeling and matching of internal components. Topics discussed include: concept recognition, hydrodynamic motion interaction with OWC, local resource evaluation, turbine selection, power generation and dissipation, moorings, data monitoring, telemetry and performance evaluation. Mathematical simulations and tank testing were used to develop the concept to a stage where an engineering design could be generated. The use of mathematical modelling presented the project with several specific problems that have been highlighted within the paper. Tank testing enabled the project to overcome these difficulties and developed an engineering design tuned to the local wave climate. Initial research has indicated that the combination of individual Oscillating Water Columns (OWC) of different draughts increases the efficiency of this design when compared to a typical single OWC device. Results also indicated that the channeling of individual air masses through a self-rectifying impulse turbine would produce a self-regulated electrical output via phase locking of the individual columns.

Power Output Performance and Smoothing Ability of an Oscillating Water Column Array Wave Energy Converter

2013 ◽  
Author(s):  
Keith O’Sullivan ◽  
Jimmy Murphy ◽  
Dara O’Sullivan
Keyword(s):  
Time Series ◽  
Water Column ◽  
Wind Turbines ◽  
Wave Energy ◽  
Power Output ◽  
Output Signal ◽  
Electrical Power ◽  
Wave Energy Converter ◽  
Oscillating Water Column ◽  
Energy Converter

This paper presents the physical model testing results of a floating oscillating water column (OWC) array wave energy converter (WEC) and the power smoothing ability inherent in the OWC chamber arrangement in the structure. The device can be categorised as a very large floating structure (VLFS) with structure dynamics which may make it a suitable device on which to mount wind turbines. It incorporates 32 individual OWC chambers in a “V” shaped arrangement such that there is a phase-lag between successive wave crests in the OWC chambers as an individual wave passes the structure. This OWC array was tested in both monochromatic and panchromatic unidirectional wave fields and the motion response amplitude operators (RAO) have been calculated. The time series of absorbed power from panchromatic waves was then used as input to a simple Well’s turbine power take-off (PTO) Simulink model to estimate the electrical power produced by each chamber and the additive power produced by the 32 OWC’s. A simple control law of optimum speed of the generator was used for these simulations. The time series of total electrical power from the 32 chambers was compared to the time series of an individual chamber and the standard deviation of the signals were also compared. The OWC array achieved a much smoother power output signal than a device with one chamber. Further smoothing of the output signal is possible by increasing the inertia of the turbine however, this may have implications for the mean efficiency of the power train. A preliminary design of the Well’s turbine is included, both in terms of mechanical parts and generator rating. This paper focusses on the power absorption and motion performance of the device and discusses the potential for the addition of wind turbines.

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