Analysis of the hydrodynamic properties of the 3-column Spar platform for offshore wind turbines

The article presents a design of a floating platform for offshore wind turbines. The concept is a modification of the Spar design and consists of three variable section columns connected to each other by a ballast tank in the lower part of the platform. This solution makes it possible to influence the position of the centre of buoyancy and the centre of mass of the structure. Compared to the classic Spar platform structure, the centre of buoyancy can be higher than mid-draft, which will provide the platform with greater stability. At the same time, this concept is better, in terms of technology, because of its modular structure and smaller bending radii.On the basis of the model testing performed, the hydrodynamic coefficients of the designed platform and its response to a given regular wave were determined (the transfer functions for heave and pitch motion were determined). Then, based on the damping coefficients, the platform was modelled in the ANSYS AQWA program and the results were very similar.