Experimental investigation on the hydrodynamic performance of a wave energy converter

Abstract Floating-type wave energy converter has the advantages of high wave energy conversion efficiency, strong shock resistance ability in rough sea and stable output power. So it is regarded as a promising energy utilization facility. The research on hydrodynamic performance of wave capture buoys is the precondition and key to the wave energy device design and optimization. A simplified motion model of the buoys in the waves is established. Based on linear wave theory, the equations of motion of buoys are derived according to Newton’s second law. The factors of wave and buoys structural parameters on wave energy absorption efficiency are discussed in the China’s Bohai Sea with short wave period and small wave height. The results show that the main factor which affects the dynamic responses of wave capture buoys is the proximity of the natural frequency of buoys to the wave period. And the incoming wave power takes a backseat role to it at constant wave height. The buoys structural parameters such as length, radius and immersed depth, influence the wave energy absorption efficiency, which play significant factors in device design. The effectiveness of this model is validated by the sea tests with small-sized wave energy devices. The establishment methods of motion model and analysis results are expected to be helpful for designing and manufacturing of floating-type wave energy converter.

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Nonlinear Time-Domain Simulation of the Heaving-Buoy Type Wave Energy Converter by Using Three-Dimensional Potential Numerical Wave Tank Under Irregular Wave Conditions

Volume 9: Ocean Renewable Energy ◽

10.1115/omae2020-18392 ◽

2020 ◽

Author(s):

Sung-Jae Kim ◽

Weoncheol Koo ◽

Moo-Hyun Kim

Keyword(s):

Wave Energy ◽

Time Domain ◽

Three Dimensional ◽

Wave Energy Converter ◽

Hydrodynamic Performance ◽

Numerical Wave Tank ◽

Energy Converter ◽

Wave Tank ◽

Type Wave ◽

Numerical Wave

Abstract The aim of this paper is to evaluate the hydrodynamic performance of a heaving buoy type wave energy converter (WEC) and power take-off (PTO) system. To simulate the nonlinear behavior of the WEC with PTO system, a three-dimensional potential numerical wave tank (PNWT) was developed. The PNWT is a numerical analysis tool that can accurately reproduce experiments in physical wave tanks. The developed time-domain PNWT utilized the previously developed NWT technique and newly adopted the side wall damping area. The PNWT is based on boundary element method with constant panels. The mixed Eulerian-Lagrangian method (MEL) and acceleration potential approach were adopted to simulate the nonlinear behaviors of free-surface nodes associated with body motions. The PM spectrum as an irregular incident wave condition was applied to the input boundary. A floating or fixed type WEC structure was placed in the center of the computational domain. A hydraulic PTO system composed of a hydraulic cylinder, hydraulic motor and generator was modeled with approximate Coulomb damping force and applied to the WEC system. Using the integrated numerical model of the WEC with PTO system, nonlinear interaction of irregular waves, the WEC structure, and the PTO system were simulated in the time domain. The optimal hydraulic pressure of the PTO condition was predicted. The hydrodynamic performance of the WEC was evaluated by comparing the linear and nonlinear analytical results and highlighted the importance accounting for nonlinear free surfaces.

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Analysis of the Hydrodynamic Performance of an Oyster Wave Energy Converter Using Star-CCM+

Journal of Marine Science and Application ◽

10.1007/s11804-019-00076-8 ◽

2019 ◽

Vol 18 (2) ◽

pp. 153-159

Author(s):

Zheng Yuan ◽

Liang Zhang ◽

Binzhen Zhou ◽

Peng Jin ◽

Xiongbo Zheng

Keyword(s):

Wave Energy ◽

Wave Energy Converter ◽

Hydrodynamic Performance ◽

Energy Converter

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Design and Hydrodynamic Performance Testing of One-Base Multi-Buoy Floating Sharp Eagle Wave Energy Converter

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1092-1093.152 ◽

2015 ◽

Vol 1092-1093 ◽

pp. 152-157

Author(s):

Zhen Peng Wang ◽

Ya Ge You ◽

Ya Qun Zhang ◽

Song Wei Sheng ◽

Hong Jun Lin

Keyword(s):

Wave Energy ◽

High Efficiency ◽

Performance Testing ◽

Clean Energy ◽

Wave Energy Converter ◽

Hydrodynamic Performance ◽

Wave Direction ◽

Energy Converter ◽

Working Principle ◽

Period Wave

Research on wave energy extraction has been conducted in many countries to meet the growing demand for clean energy. To find an efficient and economic way to convert wave energy, an one-base multi-buoy offshore floating Sharp Eagle wave energy converter is designed, consisting of four Eagle head absorbing buoys, one semi-submersible barge, one energy conversion system, buoyancy tanks, underwater appendages and other components. The working principle of the device is described in this paper. To test the hydrodynamic performance of device and make an initial evaluation for the design, a model experiment of 1/13.78th scale was carried out. The influence of wave period, wave height, pressure in hydrocylinders and wave direction is tested. All the efficiencies in different conditions are compared with each other, while the high efficiency and stability of device are verified.

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