Open AccessDIFFRACTION OF GRAVITY WAVES BY LARGE ISLANDS
Author(s) -
Peter Leth Christiansen
Publication year - 1974
Publication title -
proceedings of conference on coastal engineering/proceedings of ... conference on coastal engineering
Language(s) - English
Resource type - Journals
eISSN - 2156-1028
pISSN - 0589-087X
DOI - 10.9753/icce.v14.34
Subject(s) - diffraction , refraction , scattering , physics , regular polygon , uniform theory of diffraction , gravitational wave , geometry , exponent , optics , classical mechanics , mathematics , quantum mechanics , linguistics , philosophy
The combined refraction and diffraction of long gravity water waves for certain depth variations around large islands is investigated analytically in a circular-symmetric geometry. Creeping waves are shown to exist for bottom profiles less convex than required by the trapping criterion due to Longuet-Higgins and Shen et al. From an asymptotic representation of the solution to the scattering problem the decay exponent and the diffraction coefficient is extracted. These "canonical" quantities may then be used for the construction of diffracted fields around smooth islands of more complex shape in accordance with J.B. Keller's Geometrical Theory of Diffraction.