The hydrodynamic behaviour of long floating structures in directional seas

The diffraction/radiation boundary value problem arising from the interaction of oblique waves with freely floating long structures is studied using finite-element techniques. Further, the hydrodynamic behaviour of two-dimensional horizontal floating structures under the action of multi-directional waves has been studied. The linear transfer function approach is used to determine the wave exciting forces and motion responses of a structure of finite length in short-crested seas. The directional spectrum is obtained from a unidirectional spectrum with an associated frequency-dependent or frequency-independent cosine power-type energy spreading function. Based on the numerical predictions, the motions and forces on a rectangular floating structure experiencing unidirectional and multidirectional wave fields are computed.