Wave-current Interaction With Floating Objects With Square and Circular Waterplane Areas

Floating pontoons of different shapes are used commonly as the base of floating offshore wind turbines, and as wave breakers to mitigate severity of incoming waves. The pontoons are typically attached to catenary mooring lines and often operate in areas subject to large environmental loads, including waves, current and wind. It is of interest to analyse the wave-current interaction with pontoons of various shapes, and assess the effect of the shape of the body, wave-current direction, and the mooring lines on the loads and responses. In this study, attention is con-fined to wave-current interaction with floating objects with square and circular waterplane areas. A range of wave conditions is considered and the solution is obtained by the Green-function method for small forward speeds within the context of the linear wave diffraction theory. Results include the wave-current-induced forces, and the motion of the body. Both conditions of freely floating and objects attached to catenary mooring lines are considered, subject to various wave-current directions. Computations are carried out in frequency domain and results of the two models are compared with each other. Discussion is provided on the effect of the mooring lines and the wave-current direction on the responses of the objects.