Finite Element Analysis for Water Turbine of Horizontal Axis Rotor Wave Energy Converter

2014 ◽  
Vol 530-531 ◽  
pp. 906-910
Author(s):  
Dong Dong Hu ◽  
Yan Jun Liu ◽  
Li Kang Hong ◽  
Xiao Chen Guo
Keyword(s):  
Finite Element ◽  
Stress Response ◽  
Wave Energy ◽  
Stress Responses ◽  
Wave Energy Converter ◽  
Horizontal Axis ◽  
Linear Wave ◽  
Energy Converter ◽  
Element Analysis ◽  
Water Turbine

Horizontal axis rotor wave energy converter is a new form for utilization of ocean wave energy, and the axis of its water turbine is parallel with the sea level and perpendicular to the direction of wave. This paper employed the linear wave theory and Froude-Krylov presumptive method to calculate the wave force, which was exerted on the wave energy converter in extremely arduous wave conditions. The finite element research on the deformation and the stress response of the water turbine was carried out to assess its security. The results show that the deformation and the stress responses both reach their maximum values at the 3rd mode shape about 90Hz, and the deformation response is 0.4208mm and the stress response is 0.8052MPa at this frequency, which are both within the required security range.

Numerical Simulation of Duck Wave Energy Converter

2016 ◽  
Vol 693 ◽  
pp. 484-490
Author(s):  
Ying Xue Yao ◽  
Hai Long Li ◽  
Jin Ming Wu ◽  
Liang Zhou
Keyword(s):  
Numerical Simulation ◽  
Wave Energy ◽  
Pitch Angle ◽  
Low Cost ◽  
Three Dimensional ◽  
Angular Frequency ◽  
Wave Energy Converter ◽  
Linear Wave ◽  
Energy Converter ◽  
Flow Theories

Duck wave energy converter has the advantages of high conversion efficiency, simple construction, low cost relative to other wave power device. In the paper, the numerical simulation of the response of the converter was calculated by the AQWA software which based on the three dimensional potential flow theories. The results show that the pitch angle appear the peak when the incident wave frequency is 1rad/s and the maximum of the pitch angle come out as the linear wave normally incident the duck body, which means duck wave energy converter can absorb more wave energy in this angular frequency. The above research can provide reference for the design of the duck wave energy converter.

A Joint Numerical and Experimental Study of a Surging Point Absorbing Wave Energy Converter (WRASPA)

2009 ◽  
Author(s):  
Majid A. Bhinder ◽  
Clive G. Mingham ◽  
Derek M. Causon ◽  
Mohammad T. Rahmati ◽  
George A. Aggidis ◽  
...  
Keyword(s):  
Wave Energy ◽  
Informed Choice ◽  
Wave Energy Converter ◽  
Body Motion ◽  
Numerical Dissipation ◽  
Small Scale ◽  
Linear Wave ◽  
Energy Converter ◽  
Non Linear ◽  
Experimental Project

This paper presents the findings from using several commercial computational fluid dynamics codes in a joint numerical and experimental project to simulate WRASPA, a new wave energy converter (WEC) device. A series of fully 3D non-linear simulations of WRASPA are presented. Three commercial codes STAR-CCM, CFX and FLOW-3D are considered for simulating the WRASPA device and final results are presented based on the use of Flow-3D. Results are validated by comparison to experimental data obtained from small scale tank tests undertaken at Lancaster University (LU). The primary aim of the project is to use numerical simulation to optimize the collector geometry for power production over a range of likely wave climates. A secondary aim is to evaluate the ability of commercial codes to simulate rigid body motion in linear and non-linear wave climates in order to choose the optimal code with respect to compute speed and ease of problem setup. Issues relating to the ability of a code in terms of numerical dissipation of waves, wave absorption, wave breaking, grid generation and moving bodies will all be discussed. The findings of this paper serve as a basis for an informed choice of commercial package for such simulations. However the capability of these commercial codes is increasing with every new release.

A point absorber wave energy converter with nonlinear hardening spring power-take-off systems in regular waves

2020 ◽  
Vol 234 (4) ◽  
pp. 820-829
Author(s):  
Zhongqiang Zheng ◽  
Zhipeng Yao ◽  
Zongyu Chang ◽  
Tao Yao ◽  
Bo Liu
Keyword(s):  
Nonlinear Wave ◽  
Conversion Efficiency ◽  
Wave Energy ◽  
Wave Energy Converter ◽  
Linear Wave ◽  
Regular Waves ◽  
Energy Converter ◽  
Point Absorber ◽  
Frequency State ◽  
Nonlinear Hardening

Point absorber wave energy converter is one of the most effective wave energy harness devices. Most of the wave energy converters generate energy by oscillating the floating body. Usually, the power-take-off system is simplified as a linear spring and a linear damper. However, the narrow frequency bandwidth around a particular resonant frequency is not suitable for real vibrations applications. Thus, a nonlinear hardening spring and a linear damper are applied in the power-take-off system. The bandwidth of hardening mechanism is discussed. The dynamic model of wave energy converter is built in regular waves with time domain method. The results show that the nonlinear wave energy converter has higher conversion efficiency than the linear wave energy converter more than the natural frequency state. The conversion efficiency of the nonlinear wave energy converter in the low frequency state is closed to the linear converter. The amplitude of the incident wave, the damping of the nonlinear wave energy converter and the nonlinear parameter [Formula: see text] affect the energy capture performance of the wave energy converter.

Fatigue Analysis of a Point Absorber Wave Energy Converter Subjected to Passive and Reactive Control

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
A. S. Zurkinden ◽  
S. H. Lambertsen ◽  
L. Damkilde ◽  
Z. Gao ◽  
T. Moan
Keyword(s):  
Fatigue Damage ◽  
Wave Energy ◽  
Stress Responses ◽  
Fatigue Analysis ◽  
Wave Energy Converter ◽  
Wave Loads ◽  
Reactive Control ◽  
Energy Converter ◽  
Set Up ◽  
Frequency Domain Approach

This paper investigates the effect of a passive and reactive control mechanism on the accumulated fatigue damage of a wave energy converter (WEC). Interest is focused on four structural details of the Wavestar arm, which is used as a case study here. The fatigue model is set up as an independent and generic toolbox, which can be applied to any other global response model of a WEC device combined with a control system. The stress responses due to the stochastic wave loads are computed by a finite element method (FEM) model using the frequency-domain approach. The fatigue damage is calculated based on the spectral-based fatigue analysis in which the fatigue is described by the given spectral moments of the stress response. The question will be discussed, which control case is more favorable regarding the tradeoff between fatigue damage reduction and increased power production.

Design and test of a novel two-body direct-drive wave energy converter

2020 ◽  
pp. 1-18
Author(s):  
Chuan Liu ◽  
Renwen Chen ◽  
Yuxiang Zhang ◽  
Wen Liu ◽  
Liping Wang ◽  
...  
Keyword(s):  
Permanent Magnet ◽  
Wave Energy ◽  
Fem Simulation ◽  
Wave Theory ◽  
Wave Energy Converter ◽  
Linear Wave ◽  
Direct Drive ◽  
Energy Converter ◽  
Motion Equations ◽  
Linear Generator

As a renewable energy, ocean wave energy is exploited with infinite potential to solve the energy crisis. In this study, we develop a novel two-body direct-drive wave energy converter (DD-WEC) to surmount the problems associated with low power density, low direct-drive speed of the buoys, seawater corrosion and maintenance in the existing two-body WEC. Its prototype consists of two cylindrical buoys are utilized that float horizontally at sea level and the Halbach permanent magnet linear generator (HPMLG) that is employed in the power take-off (PTO) system. The energy is extracted from the relative motion between two buoys oscillating. Compared with the existing WEC, the proposed WEC has more vigorous motion between buoys, higher conversion efficiency and little extra underwater structure, due to the utilization of the horizontal buoys and the HPMLG. First, the motion equations of buoys are derived on the basis of linear wave theory. And depending on the motion equations, the structure of buoys and the HPMLG is designed. And we found that compared with the existing WEC, the proposed WEC has more vigorous motion between buoys in the seawater waves oscillation. Then, based on finite-element method (FEM), the performance of the HPMLG is evaluated, and it can generate 19% more power than the traditional permanent magnet linear generator (TPMLG) based on the same wave motion. Finally, the DD-WEC prototype is manufactured based on the designed parameter. The manufactured prototype is tested in the test platform and the wave tank. The measured output voltage is highly consistent with the observed variation trends in FEM simulation data. The results show that the proposed DD-WEC is well suited for wave energy conversion.

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