Renewable Energy, Vol.159, 250-271, 2020
Numerical analysis of a new multi-body floating wave energy converter with a linear power take-off system
A floating wave energy converter (FWEC) with central buoy (CB), circumferentially connected by a set of four, smoothly-finished tubular floats is proposed. The central buoy and floats are connected rigidly at one end while the other end is hinged, enabling a relative motion. The rotation of floats about the CB represents the energy extraction mode of the device. Float shapes of five different configurations, including a newly-proposed 'bean float,' are investigated to estimate their power outputs with linear PTO. FWEC remains afloat and re-centered using taut-moored tethers. The frequency-domain model is utilized to determine the hydrodynamic coefficients of the device, assuming a Potential Wave Theory (PWT). The research evaluates the impact of the obtained hydrodynamic coefficients on the average power absorbed by the FWEC. The influence of a linear power take-off (PTO) system on the average power output of FWEC is studied by optimization of the damping coefficients for the encountered regular waves. Further, time-domain analysis is carried out on the 'bean float' FWEC configuration using an open-source computer-aided engineering tool called WEC-Sim (Wave Energy Converter Simulator), and MATLAB (R) Simulink (R) implementing nonlinear buoyancy and Froude-Krylov forces. (c) 2020 Elsevier Ltd. All rights reserved.
Keywords:Floating wave energy converter;Point absorber;Nonlinear Froude-Krylov;Multi-body WEC;Power take-off