Hostname: page-component-8448b6f56d-sxzjt Total loading time: 0 Render date: 2024-04-25T00:10:28.550Z Has data issue: false hasContentIssue false

Mathematical aspects of trapping modes in the theory of surface waves

Published online by Cambridge University Press:  21 April 2006

F. Ursell
Affiliation:
Department of Mathematics, University of Manchester, Manchester M13 9PL, UK

Abstract

A horizontal canal of infinite length and of constant width and depth contains inviscid fluid under gravity. The fluid is bounded internally by a submerged horizontal cylinder which extends right across the canal and has its generators normal to the sidewalls. Suppose that the fluid is set in motion by a surface pressure varying across the canal, then some of the energy is radiated to infinity while some of the energy is trapped in characteristic modes (bound states) near the cylinder. The existence of trapping modes in special cases was shown by Stokes (1846) and Ursell (1951); a general treatment, given by Jones (1953), is based on the theory of elliptic partial differential equations in unbounded domains. In the present paper a much simpler treatment is given which uses only the theory of bounded symmetric linear operators together with Kelvin's minimum-energy theorem of classical hydrodynamics.

Type
Research Article
Copyright
© 1987 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Aranha, J. A. P. 1986 Trapped wave and non-linear resonance in semi-submersible. Proc. First Intl Workshop on Water Waves and Floating Bodies, MIT, pp. 1317.
Courant, R. & Hilbert, D. 1931 Methoden der Mathematischen Physik, vol. 1, 2nd edn. Springer.
Evans, D. V. & McIver, P. 1984 Edge waves over a shelf: full linear theory. J. Fluid Mech. 142, 7995.Google Scholar
Jones, D. S. 1953 The eigenvalues of ∇2u + λu = 0 when the boundary conditions are given on semi-infinite domains. Proc. Camb. Phil. Soc. 49, 668684.Google Scholar
Lamb, H. 1932 Hydrodynamics, 6th edn. Cambridge University Press.
McIver, P. & Evans, D. V. 1985 The trapping of surface waves above a submerged, horizontal cylinder. J. Fluid Mech. 151, 243255.Google Scholar
Riesz, F. & Sz-Nagy, B. 1952 Leçons d' Analyse Fonctionelle. Budapest: Hungarian Academy of Sciences.
Stokes, G. C. 1846 Report on recent researches in hydrodynamics. Brit. Assn Rep.
Ursell, F. 1951 Trapping modes in the theory of surface waves. Proc. Camb. Phil. Soc. 47, 347358.Google Scholar
Ursell, F. 1952 Edge waves on a sloping beach. Proc. R. Soc. Lond. A 214, 7997.Google Scholar
Ursell, F. 1968 The expansion of water-wave potentials at great distances. Proc. Camb. Phil. Soc. 64, 811826.Google Scholar
Ursell, F. 1973 On the exterior problems of acoustics. Proc. Camb. Phil. Soc. 74, 117125.Google Scholar
Weinstein, A. & Stenger, W. 1972 Methods of Intermediate Problems for Eigenvalues. Academic.