A Flexible Seafloor Carpet for High-Performance Wave Energy Extraction

2012 ◽  
Author(s):  
Mohammad-Reza Alam
Keyword(s):  
Wave Energy ◽  
High Performance ◽  
High Efficiency ◽  
Storm Surges ◽  
Energy Extraction ◽  
Energy Devices ◽  
Ocean Wave Energy ◽  
Ocean Renewable Energy ◽  
High Fraction ◽  
Extraction Scheme

Similar to the mechanism by which a visco-elastic mud damps the energy of overpassing surface waves, if the near-shore seafloor is carpeted by an elastic thin material attached to generators (i.e. dampers) a high fraction of surface wave energy can be absorbed. Here we present analytical modeling of the flexible carpet wave energy converter and show that a high efficiency is achievable. Expressions for optimal damping and stiffness coefficients are derived and different modes of oscillations are discussed. The presented wave energy conversion scheme is completely under the water surface hence imposes minimal danger to boats and the sea life (i.e. no mammal entanglement). The carpet is survivable against high momentum of storm surges and in fact can perform well under very energetic (e.g. stormy) sea conditions, when most existing wave energy devices are needed to shelter themselves by going into an idle mode. I am honored to be a colleague of Prof. Ronald Yeung at the University of California, Berkeley. He is a world renowned scientist of ship hydrodynamics with several valuable and key contributions to the field. This manuscript on a new ocean wave energy extraction scheme is due to Ron’s recent interest in the field of ocean renewable energy. I am looking forward to years of working closely with him. Thank you Ron.

scholarly journals Wave power extraction from a bottom-mounted oscillating water column converter with a V-shaped channel

2014 ◽  
Vol 470 (2167) ◽  
pp. 20140074 ◽  
Author(s):  
Zhengzhi Deng ◽  
Zhenhua Huang ◽  
Adrian W. K. Law
Keyword(s):  
Water Column ◽  
Water Depth ◽  
Wave Energy ◽  
High Efficiency ◽  
Expansion Method ◽  
Opening Angle ◽  
Energy Extraction ◽  
Oscillating Water Column ◽  
Wave Direction ◽  
Power Extraction

An analytical theory is developed for an oscillating water column (OWC) with a V-shaped channel to improve the pneumatic efficiency of wave energy extraction. An eigenfunction expansion method is used in a cylindrical coordinate system to investigate wave interaction with the OWC converter system. Auxiliary functions are introduced to capture the singular behaviours in the velocity field near the salient corners and cusped edges. Effects of the OWC dimensions, the opening angle and length of the V-shaped channel, as well as the incident wave direction, on the pneumatic efficiency of wave energy extraction are examined. Compared with a system without the V-shaped channel, our results show that the V-shaped channel can significantly increase the conversion efficiency and widen the range of wave frequency over which the OWC system can operate at a high efficiency. For typical coastal water depths, the OWC converter system can perform efficiently when the diameter of the OWC chamber is in the range of 1 5 – 1 2 times the water depth, the opening angle of the V-shaped channel is in the range of [ π /2, 3 π /4] and the length of the V-shaped channel is in the range of 1–1.5 times the water depth.

Coordinators Overview and Lessons Learned From the Galway Bay Seatrials of the FP7 EU Funded CORES Wave Energy Project

2013 ◽  
Author(s):  
Raymond Alcorn ◽  
Anthony Lewis ◽  
Mark Healy
Keyword(s):  
Renewable Energy ◽  
Wave Energy ◽  
Energy Systems ◽  
Project Manager ◽  
Lessons Learned ◽  
Ocean Energy ◽  
Renewable Energy Systems ◽  
Energy Devices ◽  
Ocean Renewable Energy ◽  
The Coordinator

The paper discusses the lessons learned from the European Funded Framework 7 Research project Components for Ocean Renewable Energy Systems (CORES) which developed and trialed new components and systems for ocean energy devices. The authors are the coordinator and project manager so the paper will give this overview of the project. This will include detail of the work packages, major achievements, significant impacts, summary results and outcomes of the sea trials.

scholarly journals A Wave Energy Extraction System in Experimental Flume

2016 ◽  
Vol 2016 ◽  
pp. 1-4
Author(s):  
Qin Guodong ◽  
Pang Quanru ◽  
Chen Zhongxian
Keyword(s):  
Wave Energy ◽  
Ocean Waves ◽  
High Energy ◽  
Ocean Wave ◽  
High Energy Density ◽  
Extraction System ◽  
Energy Extraction ◽  
Linear Generator ◽  
Ocean Wave Energy ◽  
Experimental Flume

Ocean wave energy is a high energy density and renewable resource. High power conversion rate is an advantage of linear generators to be the competitive candidates for ocean wave energy extraction system. In this paper, the feasibility of a wave energy extraction system by linear generator has been verified in an experimental flume. Besides, the analytical equations of heaving buoy oscillating in vertical direction are proposed, and the analytical equations are proved conveniently. What is more, the active power output of linear generator of wave energy extraction system in experimental flume is presented. The theoretical analysis and experimental results play a significant role for future wave energy extraction system progress in real ocean waves.

A Conceptual Overtopping Wave Energy Convertor Suitable for Small Waves

2010 ◽  
Author(s):  
John T. Imamura ◽  
Alaa Mansour
Keyword(s):  
Wave Energy ◽  
Water Waves ◽  
Energy Resource ◽  
High Energy ◽  
Wave Activity ◽  
Design Concept ◽  
Ocean Water ◽  
Large Wave ◽  
Energy Devices ◽  
Ocean Wave Energy

This paper proposes a design concept in the area of overtopping ocean wave energy devices. Current models of overtopping devices are limited to locations which experience large wave activity. The high energy associated with large waves enables the ocean water waves to overtop the device ramp into the collection reservoir which discharges through a power generating turbine. The ramp height is necessarily large to establish a sufficient collection reservoir head. The proposed design concept can utilize small waves by implementing a gearing system which can transfer water to the collection reservoir. This allows for greater access to the wave energy resource at more locations than currently possible. A simplified model of this design concept is presented and applied to varying wave conditions off the coast of California.

Design and Analysis of Water Turbine that Used for Wave Energy Power Generation

2013 ◽  
Vol 753-755 ◽  
pp. 1431-1436
Author(s):  
Shi Ming Wang ◽  
Ya Nan Wang ◽  
Ka Tian
Keyword(s):  
Wave Energy ◽  
High Efficiency ◽  
Wave Theory ◽  
Ocean Wave ◽  
Machine Design ◽  
Ocean Wave Energy ◽  
Design Structure ◽  
Fluent Simulation ◽  
Water Turbine ◽  
Control Equation

In view of the current global energy shortage crisis, ocean wave energy is development potential renewable energy, which is gaining more and more attention. This paper put forward use the water turbine absorb wave energy, and then generate electricity. It focus on the compose and generate mechanism of water turbine, and design structure of water turbine, and combine ocean wave theory and the flow control equation to analysis, through the method of machine design and FLUENT simulation, finally proved the water turbine had a high efficiency and has good application prospect.

scholarly journals Simple Controllers for Wave Energy Devices Compared

2020 ◽  
Vol 8 (10) ◽  
pp. 793
Author(s):  
Demián García-Violini ◽  
Nicolás Faedo ◽  
Fernando Jaramillo-Lopez ◽  
John V. Ringwood
Keyword(s):  
Wave Energy ◽  
Pid Controller ◽  
High Performance ◽  
Impedance Matching ◽  
Computational Cost ◽  
Numerical Algorithms ◽  
Control Engineering ◽  
Physical Constraints ◽  
Energy Devices

The design of controllers for wave energy devices has evolved from early monochromatic impedance-matching methods to complex numerical algorithms that can handle panchromatic seas, constraints, and nonlinearity. However, the potential high performance of such numerical controller comes at a computational cost, with some algorithms struggling to implement in real-time, and issues surround convergence of numerical optimisers. Within the broader area of control engineering, practitioners have always displayed a fondness for simple and intuitive controllers, as evidenced by the continued popularity of the ubiquitous PID controller. Recently, a number of energy-maximising wave energy controllers have been developed based on relatively simple strategies, stemming from the fundamentals behind impedance-matching. This paper documents this set of (5) controllers, which have been developed over the period 2010–2020, and compares and contrasts their characteristics, in terms of energy-maximising performance, the handling of physical constraints, and computational complexity. The comparison is carried out both analytically and numerically, including a detailed case study, when considering a state-of-the-art CorPower-like device.

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