Numerical Modelling of a Heaving Point Absorber in Front of a Vertical Wall

2013 ◽  
Author(s):  
Julius Schay ◽  
Joydip Bhattacharjee ◽  
C. Guedes Soares
Keyword(s):  
Numerical Modeling ◽  
Numerical Modelling ◽  
Vertical Wall ◽  
Large Body ◽  
Hydrodynamic Performance ◽  
Large Structure ◽  
Energy Converter ◽  
Point Absorber ◽  
Individual Point ◽  
Heading Angle

The hydrodynamic performance of a heaving point absorber as a wave energy converter near a large body is studied through numerical modeling. First the study is performed for an individual point absorber in the absence of large structure and the results are compared with the results available in the literature. Next, the performance of a point absorber floating in the vicinity of a large body, which is considered as a fixed vertical wall, is investigated. The efficiency of the power absorption in regular and irregular seas is examined based on different floater sizes, floater shapes, drafts, wave heading angle and positioning of the floater. Numerical simulations are based on hydrodynamic forces and coefficients, obtained with the commercial software WAMIT.

Non-linear numerical modeling and experimental testing of a point absorber wave energy converter

2014 ◽  
Vol 78 ◽  
pp. 11-21 ◽  
Author(s):  
A.S. Zurkinden ◽  
F. Ferri ◽  
S. Beatty ◽  
J.P. Kofoed ◽  
M.M. Kramer
Keyword(s):  
Numerical Modeling ◽  
Wave Energy ◽  
Experimental Testing ◽  
Wave Energy Converter ◽  
Energy Converter ◽  
Point Absorber ◽  
Non Linear

Numerical modeling on hydrodynamic performance of a bottom-hinged flap wave energy converter

2013 ◽  
Vol 27 (1) ◽  
pp. 73-86 ◽  
Author(s):  
Hai-tao Zhao ◽  
Zhi-lin Sun ◽  
Chun-ling Hao ◽  
Jia-fa Shen
Keyword(s):  
Numerical Modeling ◽  
Wave Energy ◽  
Wave Energy Converter ◽  
Hydrodynamic Performance ◽  
Energy Converter

scholarly journals Passive Model Predictive Control on a Two-Body Self-Referenced Point Absorber Wave Energy Converter

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1731
Author(s):  
Dan Montoya ◽  
Elisabetta Tedeschi ◽  
Luca Castellini ◽  
Tiago Martins
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
Wave Energy ◽  
Power Flow ◽  
Linear Constraints ◽  
Wave Energy Converter ◽  
Control Technique ◽  
Computational Time ◽  
Energy Converter ◽  
Point Absorber

Wave energy is nowadays one of the most promising renewable energy sources; however, wave energy technology has not reached the fully-commercial stage, yet. One key aspect to achieve this goal is to identify an effective control strategy for each selected Wave Energy Converter (WEC), in order to extract the maximum energy from the waves, while respecting the physical constraints of the device. Model Predictive Control (MPC) can inherently satisfy these requirements. Generally, MPC is formulated as a quadratic programming problem with linear constraints (e.g., on position, speed and Power Take-Off (PTO) force). Since, in the most general case, this control technique requires bidirectional power flow between the PTO system and the grid, it has similar characteristics as reactive control. This means that, under some operating conditions, the energy losses may be equivalent, or even larger, than the energy yielded. As many WECs are designed to only allow unidirectional power flow, it is necessary to set nonlinear constraints. This makes the optimization problem significantly more expensive in terms of computational time. This work proposes two MPC control strategies applied to a two-body point absorber that address this issue from two different perspectives: (a) adapting the MPC formulation to passive loading strategy; and (b) adapting linear constraints in the MPC in order to only allow an unidirectional power flow. The results show that the two alternative proposals have similar performance in terms of computational time compared to the regular MPC and obtain considerably more power than the linear passive control, thus proving to be a good option for unidirectional PTO systems.

scholarly journals Experimental investigation on the hydrodynamic performance of a wave energy converter

2017 ◽  
Vol 31 (3) ◽  
pp. 370-377 ◽  
Author(s):  
Xiong-bo Zheng ◽  
Yong Ma ◽  
Liang Zhang ◽  
Jin Jiang ◽  
Heng-xu Liu
Keyword(s):  
Experimental Investigation ◽  
Wave Energy ◽  
Wave Energy Converter ◽  
Hydrodynamic Performance ◽  
Energy Converter

High-performance and robust bistable point absorber wave energy converter

2021 ◽  
pp. 108767
Author(s):  
Ru Xi ◽  
Haicheng Zhang ◽  
DaolinXu ◽  
Huai Zhao ◽  
Ramnarayan Mondal
Keyword(s):  
Wave Energy ◽  
High Performance ◽  
Wave Energy Converter ◽  
Energy Converter ◽  
Point Absorber

scholarly journals Linear and nonlinear hydrodynamic models for dynamics of a submerged point absorber wave energy converter

2020 ◽  
Vol 197 ◽  
pp. 106828 ◽  
Author(s):  
Benjamin W. Schubert ◽  
William S.P. Robertson ◽  
Benjamin S. Cazzolato ◽  
Mergen H. Ghayesh
Keyword(s):  
Wave Energy ◽  
Wave Energy Converter ◽  
Hydrodynamic Models ◽  
Energy Converter ◽  
Point Absorber ◽  
Linear And Nonlinear

scholarly journals Loads on a Point-Absorber Wave Energy Converter in Regular and Focused Extreme Wave Events

2020 ◽  
Author(s):  
Eirini Katsidoniotaki ◽  
Edward Ransley ◽  
Scott Brown ◽  
Johannes Palm ◽  
Jens Engström ◽  
...  
Keyword(s):  
Wave Energy ◽  
Wave Train ◽  
Offshore Structures ◽  
Wave Energy Converter ◽  
Extreme Waves ◽  
Extreme Wave ◽  
Energy Converter ◽  
Point Absorber ◽  
Wave Energy Converters ◽  
Extreme Loads

Abstract Accurate modeling and prediction of extreme loads for survivability is of crucial importance if wave energy is to become commercially viable. The fundamental differences in scale and dynamics from traditional offshore structures, as well as the fact that wave energy has not converged around one or a few technologies, implies that it is still an open question how the extreme loads should be modeled. In recent years, several methods to model wave energy converters in extreme waves have been developed, but it is not yet clear how the different methods compare. The purpose of this work is the comparison of two widely used approaches when studying the response of a point-absorber wave energy converter in extreme waves, using the open-source CFD software OpenFOAM. The equivalent design-waves are generated both as equivalent regular waves and as focused waves defined using NewWave theory. Our results show that the different extreme wave modeling methods produce different dynamics and extreme forces acting on the system. It is concluded that for the investigation of point-absorber response in extreme wave conditions, the wave train dynamics and the motion history of the buoy are of high importance for the resulting buoy response and mooring forces.

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