scholarly journals Hydrodynamic Analysis and Optimization of a Hinged Type Wave Energy Converter

2016 ◽  
Author(s):  
Yuzhu Li ◽  
Heather Peng ◽  
Wei Qiu ◽  
Brian Lundrigan ◽  
Tim Gardiner
Keyword(s):  
Wave Energy ◽  
Second Generation ◽  
Numerical Solutions ◽  
Experimental Studies ◽  
Wave Energy Converter ◽  
Scale Model ◽  
Geometrical Parameters ◽  
Generation Model ◽  
Energy Converter ◽  
Wave Basin

SeaWEED (Sea Wave Energy Extraction Device) is a multi-body floating wave energy converter (WEC) with hinged joints developed by Grey Island Energy Inc. (GIE) in Canada. Initial conceptual studies have been carried out to evaluate the performance of the first generation device by testing a 1:16 scale model in a wave basin. The experimental results were compared with the numerical solutions. Based on the experimental studies, improvements were made and a second generation model with a new geometry of the hull and a new connection structure was developed. This paper is mainly focused on the numerical analysis and optimization of the second generation SeaWEED model. In the numerical studies, the hydraulic power take-off (PTO) system was simulated by a linear spring damper system coupled with the motion of the hinged bodies. The vertical hinge motion was computed at a series of wave periods using WAMIT. Optimization was focused on the PTO damping and the geometrical parameters in terms of the draft and the length of the truss structure between hinged bodies by using the response surface method. An optimal combination of length, draft and PTO damping was recommended for an intended operation location.

Numerical Analysis and Scaled High Resolution Tank Testing of a Novel Wave Energy Converter

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Ken Rhinefrank ◽  
Al Schacher ◽  
Joe Prudell ◽  
Joao Cruz ◽  
Chad Stillinger ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Wave Energy ◽  
Wave Energy Converter ◽  
Numerical Code ◽  
Scale Model ◽  
Energy Converter ◽  
Modeling Tools ◽  
Wave Basin ◽  
Wave Research ◽  
Multidirectional Wave

This paper presents a novel point absorber wave energy converter (WEC), developed by Columbia Power Technologies (COLUMBIA POWER), in addition to the related numerical analysis and scaled wave tank testing. Three hydrodynamic modeling tools are employed to evaluate the performance of the WEC, including WAMIT, GL Garrad Hassan's GH WaveDyn, and OrcaFlex. GH WaveDyn is a specialized numerical code being developed specifically for the wave energy industry. Performance and mooring estimates at full scale are evaluated and optimized, followed by the development of a 1:33 scale physical model. The physical tests of the 1:33 scale model WEC were conducted at the multidirectional wave basin of Oregon State University's O.H. Hinsdale Wave Research Laboratory, in conjunction with the Northwest National Marine Renewable Energy Center (NNMREC). This paper concludes with an overview of the next steps for the modeling program and future experimental test plans.

Numerical and Experimental Analysis of a Novel Wave Energy Converter

2010 ◽  
Author(s):  
Ken Rhinefrank ◽  
Al Schacher ◽  
Joe Prudell ◽  
Joao Cruz ◽  
Nuno Jorge ◽  
...  
Keyword(s):  
Wave Energy ◽  
Wave Energy Converter ◽  
Irregular Waves ◽  
Numerical Code ◽  
Scale Model ◽  
Energy Converter ◽  
Modeling Tools ◽  
Physical Experiments ◽  
Wave Basin ◽  
Wave Research

A novel point absorber wave energy converter (WEC) is being developed by Columbia Power Technologies, LLC (CPT). Numerical and physical experiments have been performed by Columbia Power, Garrad Hassan and Partners (GH) and Oregon State University (OSU). Three hydrodynamic modeling tools including WAMIT, GH WaveFarmer, and OrcaFlex are used to evaluate the performance of the WEC. GH WaveFarmer is a specialized numerical code being developed specifically for the wave energy industry. Performance and mooring estimates at full scale were initially evaluated and optimized, which were then followed by the development of a 1/33rd scale physical model to obtain comparable datasets, aiming to validate the predictions and reduce the uncertainty associated with other numerical model results. The tests of the 1/33rd scale model of the CPT WEC were recently carried out at the multi-directional wave basin of the O.H. Hinsdale Wave Research Laboratory (HWRL), in conjunction with the Northwest National Marine Renewable Energy Center (NNMREC) at OSU. This paper presents details of the modeling program and progress to date. Emphasis is given to the coupling of WAMIT with GH WaveFarmer for performance estimates and the coupling of WAMIT with the OrcaFlex model for mooring load estimates. An overview of the novel 3-body WEC, including operation and mooring system, is also presented. The 1/33rd scale model functionality is described including an overview of the experimental setup at the basin. Comparisons between the numerical and experimental results are shown for both regular and irregular waves and for several wave headings and dominant directions using a number of spreading functions. The paper concludes with an overview of the next steps for the modeling program and future experimental test plans.

Uncertainty in Wave Basin Testing of a Fixed Oscillating Water Column Wave Energy Converter

2021 ◽  
Author(s):  
Frances M. Judge ◽  
Eoin Lyden ◽  
Michael O'Shea ◽  
Brian Flannery ◽  
Jimmy Murphy
Keyword(s):  
Water Column ◽  
Wave Energy ◽  
Wave Energy Converter ◽  
Width Ratio ◽  
Oscillating Water Column ◽  
Energy Converter ◽  
The Monte Carlo Method ◽  
Wave Basin ◽  
Measurement Location ◽  
The Impact

Abstract This research presents a methodology for carrying out uncertainty analysis on measurements made during wave basin testing of an oscillating water column wave energy converter. Values are determined for Type A and Type B uncertainty for each parameter of interest, and uncertainty is propagated using the Monte Carlo method to obtain an overall Expanded Uncertainty with a 95% confidence level associated with the Capture Width Ratio of the device. An analysis into the impact of reflections on the experimental results reveals the importance of identifying the incident and combined wave field at each measurement location used to determine device performance, in order to avoid misleading results.

scholarly journals An efficient multi-factor geometry optimization based on motion analysis and resonance response for hinged double-body floating wave energy converter

2020 ◽  
Vol 103 (3) ◽  
pp. 003685042095015
Author(s):  
Biao Li ◽  
Fangfang Sui ◽  
Bingsong Yang
Keyword(s):  
Motion Analysis ◽  
Wave Energy ◽  
Geometry Optimization ◽  
Geometric Optimization ◽  
Wave Energy Converter ◽  
Geometrical Parameters ◽  
Optimization Strategy ◽  
Energy Converter ◽  
Pitching Motion ◽  
Resonance Response

In the practical engineering applications of multi-body floating wave energy converter (WEC), the traditional geometric optimization is always expensive and time-consuming. This study aim to propose a more efficient geometry optimization strategy with a hinged double-body floating WEC as the study object. The influences of geometric parameters of the buoys on the pitching motion and energy conversion ability are analyzed by numerical simulation. Simulation results show that the resonance state of the pitching motion of the buoys mainly depends on their radius and draft rather than the length; But the length of the buoys, rather than the radius and draft, always has a significant effect on the pitching phase difference of the adjacent buoys. Based on the motion analysis and resonance response, an efficient multi-factor geometry optimization strategy is put forwarded. By the strategy, the sub-optimal and optimal geometrical parameters are solved out quickly at several typical wave conditions of China Seas. The results indicate that the optimal total length of WEC is approximately equal to the wave length. The optimal diameter of buoys is about 25% of the length of buoys. And the optimal draft should attain about 61% of the diameter.

scholarly journals Numerical and Experimental Investigation on a Moonpool-Buoy Wave Energy Converter

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2364 ◽  
Author(s):  
Hengxu Liu ◽  
Feng Yan ◽  
Fengmei Jing ◽  
Jingtao Ao ◽  
Zhaoliang Han ◽  
...  
Keyword(s):  
Numerical Model ◽  
Wave Energy ◽  
Wave Energy Converter ◽  
Scale Model ◽  
Energy Converter ◽  
Point Absorber ◽  
Motion Responses ◽  
Computational Fluid Dynamics Cfd ◽  
The Time Domain ◽  
Good Agreement

This paper introduces a new point-absorber wave energy converter (WEC) with a moonpool buoy—the moonpool platform wave energy converter (MPWEC). The MPWEC structure includes a cylinder buoy and a moonpool buoy and a Power Take-off (PTO) system, where the relative movement between the cylindrical buoy and the moonpool buoy is exploited by the PTO system to generate energy. A 1:10 scale model was physically tested to validate the numerical model and further prove the feasibility of the proposed system. The motion responses of and the power absorbed by the MPWEC studied in the wave tank experiments were also numerically analyzed, with a potential approach in the frequency domain, and a computational fluid dynamics (CFD) code in the time domain. The good agreement between the experimental and the numerical results showed that the present numerical model is accurate enough, and therefore considering only the heave degree of freedom is acceptable to estimate the motion responses and power absorption. The study shows that the MPWEC optimum power extractions is realized over a range of wave frequencies between 1.7 and 2.5 rad/s.

scholarly journals Hydro-Elastic Modelling of an Electro-Active Wave Energy Converter

2013 ◽  
Author(s):  
Aurélien Babarit ◽  
Benjamin Gendron ◽  
Jitendra Singh ◽  
Cécile Mélis ◽  
Philippe Jean
Keyword(s):  
Numerical Model ◽  
Wave Energy ◽  
Ocean Basin ◽  
Wave Energy Converter ◽  
Scale Model ◽  
Linear Potential ◽  
Energy Converter ◽  
Outer Flow ◽  
Modal Expansion ◽  
Linear Potential Theory

Since 2009, SBM Offshore has been developing the S3 Wave Energy Converter (S3 WEC). It consists in a long flexible tube made of an Electro-Active Polymer (EAP). Thus, the structural material is also the Power Take Off (PTO). In order to optimize the S3 WEC, a hydro-elastic numerical model able to predict the device dynamic response has been developed. The inner flow, elastic wall deformations and outer flow are taken into account in the model under the following assumptions: Euler equation is used for the inner flow. The flow is also assumed to be uniform. Elastic deformation of the wall tube is linearized. The outer flow is modeled using linear potential theory. These equations have been combined in order to build the numerical model. First, they are solved in the absence of the outer fluid in order to obtain the modes of response of the device. Secondly, the outer fluid is taken into account and the equation of motion is solved by making use of modal expansion. Meanwhile, experimental validation tests were conducted in the ocean basin at Ecole Centrale De Nantes. The scale model is 10m long tube made of EAP. The tube deformations were measured using the electro-active polymer. The model was also equipped with sensors in order to measure the inner pressure. Comparisons of the deformation rate between the numerical model and experimental results show good agreement, provided that the wall damping is calibrated. Eventually, results of a technico-economical parametric study of the dimensions of the device are presented.

Comparison of Mooring Loads in Survivability Mode on the Wave Dragon Wave Energy Converter Obtained by a Numerical Model and Experimental Data

2012 ◽  
Author(s):  
Stefano Parmeggiani ◽  
Made Jaya Muliawan ◽  
Zhen Gao ◽  
Torgeir Moan ◽  
Erik Friis-Madsen
Keyword(s):  
Numerical Model ◽  
Wave Energy ◽  
Complex Geometry ◽  
Wave Energy Converter ◽  
Scale Model ◽  
Coupled Analysis ◽  
Small Scale ◽  
Energy Converter ◽  
Numerical Predictions ◽  
Small Scale Model

The Wave Dragon Wave Energy Converter is ready to be up-scaled to commercial size. The design and feasibility analysis of a 1.5 MW pre-commercial unit to be deployed at the DanWEC test center in Hanstholm, Denmark, is currently ongoing. With regard to the mooring system, the design has to be carried out numerically, through coupled analyses of alternative solutions. The present study deals with the preliminary hydrodynamic characterization of Wave Dragon needed in order to calibrate the numerical model to be used for the mooring design. A hydrodynamic analysis of the small scale model in the frequency domain is performed by the software HydroD, which uses WAMIT as core software. The quadratic damping term, accounting for the viscous effect, is determined through an iterative procedure aimed at matching numerical predictions on the mooring tension, derived through time domain coupled analysis, with experimental results derived from tank tests of a small scale model. Due to the complex geometry of the device, a sensitivity analysis is performed to discuss the influence of the mean position on the quality of the numerical predictions. Good correspondence is achieved between the experimental and numerical model. The numerical model is hence considered reliable for future design applications.

scholarly journals Effect of Dissipation on the Moonpool-Javelin Wave Energy Converter

2021 ◽  
Vol 9 (12) ◽  
pp. 1444
Author(s):  
Dan Yu ◽  
Keyi Wang ◽  
Yeqing Jin ◽  
Fankai Kong ◽  
Hailong Chen ◽  
...  
Keyword(s):  
Wave Energy ◽  
Potential Flow ◽  
Wave Force ◽  
Wave Energy Converter ◽  
Hydrodynamic Performance ◽  
Scale Model ◽  
Energy Converter ◽  
Viscous Term ◽  
Cfd Method ◽  
The Time Domain

In this work, the hydrodynamic performance of a novel wave energy converter (WEC) configuration which combines a moonpool platform and a javelin floating buoy, called the moonpool–javelin wave energy converter (MJWEC), was studied by semianalytical, computational fluid dynamics (CFD), and experimental methods. The viscous term is added to the potential flow solver to obtain the hydrodynamic coefficients. The wave force, the added mass, the radiation damping, the wave capture, and the energy efficiency of the configuration were assessed, in the frequency and time domains, by a semianalytical method. The CFD method results and the semianalytical results were compared for the time domain by introducing nonlinear power take-off (PTO) damping; additionally, the viscous dissipation coefficients under potential flow could be confirmed. Finally, a 1:10 scale model was physically tested to validate the numerical model and further prove the feasibility of the proposed system.

scholarly journals Hydrodynamic Performance of a Hybrid System Combining a Fixed Breakwater and a Wave Energy Converter: An Experimental Study

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5740
Author(s):  
Wei Peng ◽  
Yingnan Zhang ◽  
Xueer Yang ◽  
Jisheng Zhang ◽  
Rui He ◽  
...  
Keyword(s):  
Experimental Study ◽  
Hybrid System ◽  
Wave Energy ◽  
Wave Energy Converter ◽  
Hydrodynamic Performance ◽  
Scale Model ◽  
Wave Power ◽  
Energy Converter ◽  
Power Extraction ◽  
Wave Induced

In this paper, a hybrid system integrating a fixed breakwater and an oscillating buoy type wave energy converter (WEC) is introduced. The energy converter is designed to extract the wave power by making use of the wave-induced heave motions of the three floating pontoons in front of the fixed breakwater. A preliminary experimental study is carried out to discuss the hydrodynamic performance of the hybrid system under the action of regular waves. A scale model was built in the laboratory at Hohai University, and the dissipative force from racks and gearboxes and the Ampere force from dynamos were employed as the power take-off (PTO) damping source. During the experiments, variations in numbers of key parameters, including the wave elevation, free response or damped motion of the floating pontoons, and the voltage output of the dynamos were simultaneously measured. Results indicate that the wave overtopping and breaking occurring on the upper surfaces of floating pontoons have a significant influence on the hydrodynamic performance of the system. For moderate and longer waves, the developed system proves to be effective in attenuating the incident energy, with less than 30% of the energy reflected back to the paddle. More importantly, the hydrodynamic efficiency of energy conversion for the present device can achieve approximately 19.6% at the lowest wave steepness in the model tests, implying that although the WEC model harnesses more energy in more energetic seas, the device may be more efficient for wave power extraction in a less energetic sea-state.

Sign in / Sign up

Export Citation Format

Share Document