Wave radiation and diffraction by a two-dimensional floating rectangular body with an opening in its bottom

The radiation and diffraction problem of a two‐dimensional rectangular body with an opening in its bottom floating on a layer of water of finite depth is analysed based on the linearized velocity potential theory through an analytical solution procedure. The expressions for the potentials are obtained by the method of separation of variables, in which the unknown coefficients are determined by the boundary condition and matching requirement on the interface. The hydrodynamic coefficients and wave excitation forces are obtained and verified using the near‐field and far‐field methods and the symmetry properties of coupled hydrodynamic coefficients. The effect of the opening on the wave excitation force and hydrodynamic coefficients is investigated. Piston resonant behaviour and sloshing resonant behaviour are also investigated and their effect on the wave excitation force and hydrodynamic coefficients is discussed.