Wave deformation by a submerged flexible circular disk

The interaction of incident monochromatic waves with a tensioned, flexible, circular membrane submerged horizontally below free surface is investigate d in the frame of three-dimensional linear hydroelastic theory. The velocit y potential is split into two parts, i.e. the diffraction potential represe nting the scattering of incident waves by a rigid circular disk and the rad iation potential describing motion induced waves by elastic responses of th e flexible membrane. The fluid domain is divided into three regions, and th e diffraction and radiation potentials in each region are expressed by the Fourier-Bessel series. The displacement of the circular membrane is expande d with a set of natural functions, which satisfy the membrane equation of m otion and boundary conditions. The unknown coefficients in each region are determined by applying the continuity of pressure and normal velocity at th e matching boundaries. The results show that various types of wave focusing are possible by controlling the size, submergence depth, and tension of th e membrane. (C) 1999 Elsevier Science Ltd. All rights reserved.