Diffraction of water waves by a moored, horizontal, flat plate

A Norwegian research group has investigated the feasibility of constructing a system of underwater structures which would act like a lens and focus water waves prior to harnessing their energy. In the present work we consider modelling one of these structures by a horizontal, flat plate which is moored to the seabed. The water is assumed to be incompressible and inviscid and two-dimensional, linear, irrotational theory is used. Solutions to the scattering and radiation potentials are obtained by the method of matched eigenfunction expansions. Comparisons are made with various approximate solutions and results are presented illustrating the effect of varying the mooring stiffness in t~e cables on both the responses of the plate and the far-field wave motion.