Session: 09-02-03 Wave Energy: WEC Arrays

Paper Number: 120799

120799 - CFD Modelling of Arrays of Point-Absorber Wave Energy Converters 

Wave energy, resulting from wind-induced localized disturbances at the atmosphere-ocean interface, constitutes more than half of the ocean's total energy content. It is estimated that Earth's total available wave energy is around 2.11 TW. Considering the global energy consumption, reported by the International Energy Agency (IEA) to be approximately 17.7 TW, wave energy could theoretically satisfy over 12% of global energy demand if fully harnessed. Consequently, wave energy has attracted significant interest from both industrial and academic sectors over recent decades. It holds potential as a sustainable, power-dense, relatively predictable, and widely accessible energy source. The power capacity of point absorbers is inherently constrained by the relationship between the converter units' optimal dimensions and the dominant wavelength of the incident waves. As a result, to achieve commercial viability and competitiveness with other renewable energy sources, multiple point absorbers must be installed in an array configuration. However, due to the interaction between the point absorbers within the array, the 'park effect' must be carefully considered, as the total energy generated from an array of N WECs differs from N times the power produced by a single isolated unit. In the present paper, we adopt a high-fidelity CFD model in OpenFOAM for response of a wave energy farm consisting of 10 point-absorbing wave energy converters. The overset mesh is applied in the present numerical model, with the background mesh and the body-fitted mesh overlapping near each WEC. The heave, surge and pitch motion of different WECs in the farm are analyzed, and the interactions between them and the park effect are investigated under different wave conditions. Under long waves, the WECs can be treated as slender structures, and wave scattering effect is secondary. When the incident wave passes through the WEC farm, the disturbance of WECs on the incident wave is nearly negligible. However, significant diffraction effects are observed for WECs under short waves, leading to different responses for different WEC.

Presenting Author: Hao Chen Newcastle University in Singapore

Presenting Author Biography: Dr Chen is currently an assistant professor in Marine Technology in Newcastle University in Singapore. He received his PhD from Technical University of Denmark in 2017. Since then, he worked as research fellow in Manchester Metropolitan University and National University of Singapore, and assistant professor in University of Glasgow Singapore before he joined NU. His research interests are in coastal and marine hydrodynamics, with emphasis on numerical modelling of free surface waves including wave breaking, wave overtopping, wave-wave and wave-structure interactions. He develops computational fluid dynamic based numerical solvers to describe the physical processes and phenomena that define and influence atmospheric, oceanographic and seafloor interactions with engineered or natural offshore systems, support sustainable extractive activities related to energy generation and food and enhance the resilience of the coastal communities, economies, and ecosystems.

Authors:

Hao Chen Newcastle University in Singapore
Zaibin Lin University of Aberdeen
Hui Liang Technology Centre for Offshore and Marine, Singapore