Application of the scattering matrix theory to the hydrodynamic forces on a multi-hull structure in waves

The scattering matrix theory is applied to the diffraction and the radiation problem of the two dimensional multi-hull structure. We focus on the zeros of the wave exciting force and the near resonance, which occurs both in the diffraction problem and the radiation problem. A number of simple equations for representing the hydrodynamic properties of the multi-hull structure at the zeros and the near resonance frequency are obtained. The numerical examples show that these simple equations well explain the hydrodynamic forces as well as the wave system among the spaces between the demi-hulls.