Experimental and numerical investigation on the suitability of semi-submersible floaters to support vertical axis wind turbine

The fixed type foundation to support wind turbine in shallow water and floaters for medium to deep water depth, has been proposed in the literature. Among the floaters, semi-submersible floater has been shown promising with improved hydrodynamic response. In this study, the feasibility of semi-submersible type floater to support a vertical axis wind turbine (VAWT) has been investigated and presented. Experimental studies and numerical simulations were carried out on 3 and 4 column semi-submersible (1:75 Froude scale model) of the same displacement to assess the suitability and its hydrodynamic response in regular waves including the effect of wind turbine rotation. The damping characteristics of the floaters have been assessed using free decay tests as well as computational fluid dynamics simulations and compared. The hydrodynamic response of the floaters has been simulated using numerical simulations and the results obtained from numerical simulations were compared with that obtained from experiments. The suitability of prototype semi-submersible floaters (3-Column, and 4-Column) for supporting VAWT has been evaluated using the acceptable limits for west coast of India’s environmental conditions near Gujarat as a proposed for First Offshore Windfarm Project India (FOWPI).