Short-term wave force prediction for wave energy converter control

Accurate forecasts of ocean waves energy can not only reduce costs for investment but it is also essential for management and operation of electrical power. This paper presents an innovative approach based on the Long Short Term Memory (LSTM) to predict the power generation of an economical wave energy converter named “Searaser”. The data for analyzing is provided by collecting the experimental data from another study and the exerted data from numerical simulation of searaser. The simulation is done with Flow-3D software which has high capability in analyzing the fluid solid interactions. The lack of relation between wind speed and output power in previous studies needs to be investigated in this field. Therefore, in this study the wind speed and output power are related with a LSTM method. Moreover, it can be inferred that the LSTM Network is able to predict power in terms of height more accurately and faster than the numerical solution in a field of predicting. The network output figures show a great agreement and the root mean square is 0.49 in the mean value related to the accuracy of LSTM method. Furthermore, the mathematical relation between the generated power and wave height was introduced by curve fitting of the power function to the result of LSTM method.

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Effect of Dissipation on the Moonpool-Javelin Wave Energy Converter

Journal of Marine Science and Engineering ◽

10.3390/jmse9121444 ◽

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.

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Long-Term Stochastic Dynamic Analysis of a Combined Floating Spar-Type Wind Turbine and Wave Energy Converter (STC) System for Mooring Fatigue Damage and Power Prediction

Volume 9A: Ocean Renewable Energy ◽

10.1115/omae2014-23438 ◽

2014 ◽

Author(s):

Nianxin Ren ◽

Zhen Gao ◽

Torgeir Moan

Keyword(s):

Wind Turbine ◽

Fatigue Damage ◽

Wave Energy ◽

Wind Wave ◽

Wave Energy Converter ◽

Force Model ◽

Stochastic Dynamic ◽

Energy Converter ◽

Short Term

In this work, a combined concept called Spar-Toru-Combination (STC) involving a spar-type floating wind turbine (FWT) and an axi-symmetric two-body wave energy converter (WEC) is considered. From the views of both long-term fatigue damage prediction of the mooring lines and the annual energy production estimation, a coupled analysis of wind-wave induced long-term stochastic responses has been performed using the SIMO-TDHMILL code in the time domain, which includes 79200 one-hour short term cases (the combination of 22 selected mean wind speeds * 15 selected significant wave heights * 12 selected spectral peak wave periods * 20 random seeds). The hydrodynamic loads on the Spar and Torus are estimated using potential theory, while the aerodynamic loads on the wind rotor are calculated by the validated simplified thrust force model in the TDHMILL code. Considering the long-term wind-wave joint distribution in the northern North Sea, the annual fatigue damage of the mooring line for the STC system is obtained by using the S-N curve approach and Palmgren-Miner’s linear damage hypothesis. In addition, the annual wind and wave power productions are also obtained by using hourly mean output power for each short-term condition and the joint wind-wave distribution.

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Analysis of Hydrodynamic Model of Wave Energy Converter of Inverse Pendulum

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.483.223 ◽

2013 ◽

Vol 483 ◽

pp. 223-228

Author(s):

Shou Qi Cao ◽

Shu Man Fu ◽

Zi Yue Wu

Keyword(s):

Wave Energy ◽

Hydrodynamic Model ◽

Mechanical Energy ◽

Wave Force ◽

Wave Energy Converter ◽

Energy Converter ◽

Wave Condition ◽

Conversion Model ◽

Fluent Software ◽

Sea Area

The efficiency analysis of wave energy collection and conversion is crucial for utility of wave energy of inverse pendulum. In the paper, we build the hydrodynamic model of interaction between pendulum and wave in wave energy converter of inverse pendulum. On the basis of this typical model, we choose the actual wave condition of some sea area in the east of China as the background, research the hydrodynamic property of pendulum by numerical simulation with fluent software, get the relation curve of between the rotation angle of pendulum and moment of wave force with time, and acquire energy conversion model from wave energy to mechanical energy in wave energy converter of inverse pendulum. It makes the beneficial exploration for optimal design of wave energy converter of inverse pendulum.

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