NUMERICAL MODELLING AND ASSESSMENT OF THE UGEN FLOATING WAVE ENERGY CONVERTER

2021 ◽  
Vol 153 (A2) ◽  
Author(s):  
N Fonseca ◽  
S R Silva ◽  
J Pessoa
Keyword(s):  
Numerical Modelling ◽  
Relative Motion ◽  
Wave Energy ◽  
Hydrodynamic Model ◽  
Wave Energy Converter ◽  
Energy Converter ◽  
Rolling Mode ◽  
The Waves

The paper presents a linear hydrodynamic model for the UGEN wave energy converter, an analysis of the dynamics of the system and the predicted ability to extract energy from the waves. The UGEN (floating device with a U tank for GENeration of electricity from waves) consists of an asymmetric floater with a large internal U tank filled with water, where the energy is extracted from the relative motion between the water inside the tank and the rolling of the floater. The floater rolling mode of motion is the main stimulator of the motion of the water in the tank, however the sway and heave motions are also coupled therefore the system has motion.

scholarly journals A broadbanded pressure differential wave energy converter based on dielectric elastomer generators

2021 ◽  
Author(s):  
Michele Righi ◽  
Giacomo Moretti ◽  
David Forehand ◽  
Lorenzo Agostini ◽  
Rocco Vertechy ◽  
...  
Keyword(s):  
Wave Energy ◽  
Large Deformations ◽  
Dielectric Elastomer ◽  
Wave Energy Converter ◽  
Pressure Differential ◽  
Design Stage ◽  
Small Scale ◽  
Energy Converter ◽  
Wide Range ◽  
The Waves

AbstractDielectric elastomer generators (DEGs) are a promising option for the implementation of affordable and reliable sea wave energy converters (WECs), as they show considerable promise in replacing expensive and inefficient power take-off systems with cheap direct-drive generators. This paper introduces a concept of a pressure differential wave energy converter, equipped with a DEG power take-off operating in direct contact with sea water. The device consists of a closed submerged air chamber, with a fluid-directing duct and a deformable DEG power take-off mounted on its top surface. The DEG is cyclically deformed by wave-induced pressure, thus acting both as the power take-off and as a deformable interface with the waves. This layout allows the partial balancing of the stiffness due to the DEG’s elasticity with the negative hydrostatic stiffness contribution associated with the displacement of the water column on top of the DEG. This feature makes it possible to design devices in which the DEG exhibits large deformations over a wide range of excitation frequencies, potentially achieving large power capture in a wide range of sea states. We propose a modelling approach for the system that relies on potential-flow theory and electroelasticity theory. This model makes it possible to predict the system dynamic response in different operational conditions and it is computationally efficient to perform iterative and repeated simulations, which are required at the design stage of a new WEC. We performed tests on a small-scale prototype in a wave tank with the aim of investigating the fluid–structure interaction between the DEG membrane and the waves in dynamical conditions and validating the numerical model. The experimental results proved that the device exhibits large deformations of the DEG power take-off over a broad range of monochromatic and panchromatic sea states. The proposed model demonstrates good agreement with the experimental data, hence proving its suitability and effectiveness as a design and prediction tool.

scholarly journals Numerical Study on the Optimization of Hydrodynamic Performance of Oscillating Buoy Wave Energy Converter

2021 ◽  
Vol 28 (1) ◽  
pp. 48-58
Author(s):  
Wenbin Lai ◽  
Yonghe Xie ◽  
Detang Li
Keyword(s):  
Wave Energy ◽  
Numerical Study ◽  
Energy Conversion Efficiency ◽  
Absorption Efficiency ◽  
Wave Energy Converter ◽  
Hydrodynamic Performance ◽  
Energy Converter ◽  
Physical Experiments ◽  
Working Principle ◽  
The Waves

Abstract The oscillating buoy wave energy converter (OBWEC) captures wave energy through the undulating movement of the buoy in the waves. In the process of capturing wave energy, the hydrodynamic performance of the buoy plays an important role. This paper designed the “Haida No. 1” OBWEC, in which the buoy adopts a form of swinging motion. In order to further improve the hydrodynamic performance of the buoy, a 2D numerical wave tank (NWT) model is established using ADINA software based on the working principle of the device. According to the motion equation of the buoy in the waves, the influence of the buoy shape, arm length, tilt angle, buoy draft, buoy width, wave height and Power Take-off (PTO) damping on the hydrodynamic performance of the buoy is studied. Finally, a series of physical experiments are performed on the device in a laboratory pool. The experimental results verify the consistency of the numerical results. The research results indicate that the energy conversion efficiency of the device can be improved by optimizing the hydrodynamic performance of the buoy. However, the absorption efficiency of a single buoy for wave energy is limited, so it is very difficult to achieve full absorption of wave energy.

scholarly journals KNSwing—On the Mooring Loads of a Ship-Like Wave Energy Converter

2019 ◽  
Vol 7 (2) ◽  
pp. 29
Author(s):  
Kim Nielsen ◽  
Jonas Thomsen
Keyword(s):  
Numerical Model ◽  
Wave Energy ◽  
Numerical Models ◽  
Breaking Waves ◽  
Wave Energy Converter ◽  
Experimental Results ◽  
Irregular Waves ◽  
Mooring System ◽  
Energy Converter ◽  
The Waves

The critical function of keeping a floating Wave Energy Converter in position is done by a mooring system. Several WECs have been lost due to failed moorings, indicating that extreme loads, reliability and durability are very important aspects. An understanding of the interaction between the WEC’s motion in large waves and the maximum mooring loads can be gained by investigating the system at model scale supported by numerical models. This paper describes the testing of a novel attenuator WEC design called KNSwing. It is shaped like a ship facing the waves with its bow, which results in low mooring loads and small motions in most wave conditions when the structure is longer than the waves. The concept is tested using an experimental model at scale 1:80 in regular and irregular waves, moored using rubber bands to simulate synthetic moorings. The experimental results are compared to numerical simulations done using the OrcaFlex software. The experimental results show that the WEC and the mooring system survives well, even under extreme and breaking waves. The numerical model coefficient concerning the nonlinear drag term for the surge motion is validated using decay tests. The numerical results compare well to the experiments and, thereby, the numerical model can be further used to optimize the mooring system.

scholarly journals Numerical modelling on the performance of a rolling-type wave energy converter with mooring system

2020 ◽  
Vol 461 ◽  
pp. 012035
Author(s):  
Yichen Jiang ◽  
Yuhao Peng ◽  
Peidong Zhao ◽  
He Zhang ◽  
Hongyun Zong ◽  
...  
Keyword(s):  
Numerical Modelling ◽  
Wave Energy ◽  
Wave Energy Converter ◽  
Mooring System ◽  
Energy Converter ◽  
Type Wave

scholarly journals Optimization of an Invention Based on a Force Multiplier Mechanism for Wave Power Generation

2014 ◽  
Vol 507 ◽  
pp. 480-485
Author(s):  
Javier Aparisi ◽  
Jose González ◽  
Bernabé Hernandis
Keyword(s):  
Power Generation ◽  
Wave Height ◽  
Wave Energy ◽  
Fossil Fuels ◽  
Clean Energy ◽  
Wave Energy Converter ◽  
Wave Power ◽  
Rectilinear Motion ◽  
Energy Converter ◽  
The Waves

The development and exploitation of new sources of clean energy that do not depend on traditional sources based on the use of fossil fuels, is the focus of this research, which starts with the optimization of an invention capable of transforming a reciprocating rectilinear motion into continuous circular motion in a very efficient way, to be used in the development of a Wave Energy Converter (WEC), capable of operating with low wave height and taking advantage of the oscillating movement of the waves both when rising, and when lowering, unlike other similar devices that harness it only in one way.

Numerical modelling of a point-absorbing wave energy converter in irregular and extreme waves

2017 ◽  
Vol 63 ◽  
pp. 90-105 ◽  
Author(s):  
WenChuang Chen ◽  
Irina Dolguntseva ◽  
Andrej Savin ◽  
YongLiang Zhang ◽  
Wei Li ◽  
...  
Keyword(s):  
Numerical Modelling ◽  
Wave Energy ◽  
Wave Energy Converter ◽  
Extreme Waves ◽  
Energy Converter

Design and Analysis of a Two-Body Wave Energy Converter With Mechanical Motion Rectifier

2016 ◽  
Author(s):  
Xiaofan Li ◽  
Changwei Liang ◽  
Lei Zuo
Keyword(s):  
Output Power ◽  
Relative Motion ◽  
Wave Energy ◽  
Average Output Power ◽  
Body Wave ◽  
Wave Energy Converter ◽  
Mechanical Motion ◽  
Energy Converter ◽  
Average Output ◽  
Wave Condition

The design and dynamic analysis of a two-body wave energy converter with 50W average output power is presented in this paper. The wave energy is extracted through the relative motion between a floating buoy and a submerged body, both oscillating in the heave direction. A ball screw system is used to convert the linear relative motion into bidirectional rotation of the screw. Moreover, a mechanical motion rectifier (MMR) is used in the power take-off (PTO) design and convert the bidirectional rotation into unidirectional rotation of generator by using two one-way bearings in the gear system. The dynamic equation of this two-body wave energy converter is established by considering the engagement and disengagement of the one-way bearings in the PTO system. The simulation results in the regular and irregular waves are presented and the average output power of the proposed wave energy converter under different wave condition are estimated.

Electromechanical Modeling and Simulation of a Pendulum-Type Wave Energy Converter

2014 ◽  
Vol 953-954 ◽  
pp. 1439-1444
Author(s):  
Bao wei Song ◽  
Xin Yu An ◽  
Zhao Yong Mao ◽  
Hai Bing Wen
Keyword(s):  
Natural Frequency ◽  
Relative Motion ◽  
Wave Energy ◽  
Wave Energy Converter ◽  
Floating Body ◽  
Circuit Optimization ◽  
Energy Converter ◽  
Electromechanical Model ◽  
Type Wave ◽  
Mass Spring

This paper concerns the electromechanical model for a pendulum-type wave energy converter (PWEC). By introducing a based-excited mass-spring-damper, the motion of PWEC is divided into two parts: the motion of floating body and the relative motion of the pendulum and floating body. The electromechanical model involves the relative motion. Based on the electromechanical model, the circuit optimization is researched in frequency domain. The simulation results show that the device harvests plenty of power when the excitation is in close proximity to natural frequency, and the output power will decay sharply when the excitation is away from natural frequency. The optimal active power is obtained when the total reactance is zero.

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