Numerical study of hydrodynamic responses for a combined concept of semisubmersible wind turbine and different layouts of a wave energy converter

Wind-wave combined structures have great development potential due to larger power production that they have compared with segregated offshore wind turbines or wave energy converters. The present paper studies a combined structure of a 5-MW braceless semisubmersible floating offshore wind turbine (FOWT) and different configurations of a torus-type wave energy converter (WEC). Various configurations of the combined structure are proposed and investigated based on three-dimensional potential flow theory. Initially, the effects of the number of the WECs that are utilized in different configurations of the combined structure on the hydrodynamic performance of the semisubmersible platform are investigated in the frequency domain by comparing hydro-dynamic coefficients. The hydrodynamic coupling mechanisms of the combined structure with different number of WECs are studied. Wave contours are presented and compared to study the interaction effect of surrounding fluid with the combined structure and the examined various configurations. Response amplitude operators (RAOs) and the produced power for the examined combined structures in time domain are compared and dis-cussed, it is indicated that the combined structure with the configuration with use of three WECs has the largest produced power capacity.