Novel concept of hybrid wavestar- floating offshore wind turbine system with rectilinear arrays of WECs.

This paper deals with the novel composition of the Wavestar (WS) wave energy converter (WEC) and a floating offshore wind turbine (FOWT) as a hybrid wave-wind energy concept. Two hybrid systems with different WS diameters and numbers (namely N12D5.725 and N18D5) have been considered, in which the total WSs volume displacement for both concepts is equal. In both concepts, two rectilinear arrays of WS in three groups have been proposed. In the present study, the ANSYS-AQWA software is used to estimate the WSs performance considering hydrodynamics interaction between floating bodies. Firstly, the validation was carried out for the WS heave position and velocity response in the time domain and for the FOWT response in the frequency domain. Then, the power take-off (PTO) optimum damping coefficient for two WSs systems was obtained. Afterward, total absorbed power and capture width ratio (CWR) at various wave heights and periods are presented using the optimum damping coefficient. It is concluded that the system of N18D5 is absorbed about 12.85% more power than N12D5.725 for all wave directions. The highest and lowest power occurs in the wave direction of 75 and 0°, respectively. The hydrodynamic interaction decreases average WSs power, especially in larger wave periods. • Hybrid Wind-Wave energy coupling concept were proposed using braceless semi-submersible FOWT-Wavestars (N12D5.725 and N18D5). • Time domain and frequency domain responses of the Wavestars and braceless semi-submersible FOWT platform were analyzed. • Total absorbed power and capture width ratio (CWR) were presented and discussed under different wave heights and wave periods. • Hydrodynamic interaction between Wavestars and braceless semi-submersible FOWT are studied. [ABSTRACT FROM AUTHOR]