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Diffraction of water waves by a slotted cylindrical breakwater
Author(s) -
Basmat A.
Publication year - 2008
Publication title -
pamm
Language(s) - English
Resource type - Journals
ISSN - 1617-7061
DOI - 10.1002/pamm.200810671
Subject(s) - breakwater , diffraction , wavelength , mechanics , boundary value problem , cylinder , limiting , geometry , velocity potential , permeability (electromagnetism) , geology , materials science , physics , geotechnical engineering , mathematics , optics , mathematical analysis , engineering , chemistry , mechanical engineering , biochemistry , membrane
Permeable and slotted breakwaters are becoming more popular, in order to reduce the drawback of rigid coastal structures: namely large reflections, forces and overtopping. The linearized theory of water waves is used to examine the diffraction of incident regular waves by a vertically slotted cylindrical breakwater that consists of a number of distinct rigid cylindrical panels. Under the assumption that the wavelength is much greater than the thickness, each segment is replaced by a thin structure and the permeability is modelled by suitable boundary conditions. The first condition is the matching pressure and normal velocity conditions between two internal and external fluid regions and the second condition is zero normal velocity on rigid panels. The mixed boundary–value problem is transformed to dual series relations and the least–square method is applied to get the forces on the structure. The results are presented to illustrate the effects of permeability. Numerical results compare well with McCamy and Fuchs predictions for the limiting case of an impermeable rigid cylinder. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)