Hostname: page-component-84b7d79bbc-dwq4g Total loading time: 0 Render date: 2024-07-25T22:42:49.005Z Has data issue: false hasContentIssue false

Trapping modes in the theory of surface waves

Published online by Cambridge University Press:  24 October 2008

F. Ursell
Affiliation:
Department of MathematicsThe UniversityManchester

Abstract

It is shown that a mass of fluid bounded by fixed surfaces and by a free surface of infinite extent may be capable of vibrating under gravity in a mode (called a trapping mode) containing finite total energy. Trapping modes appear to be peculiar to the theory of surface waves; it is known that there are no trapping modes in the theory of sound. Two trapping modes are constructed: (1) a mode on a sloping beach in a semi-infinite canal of finite width, (2) a mode near a submerged circular cylinder in an infinite canal of finite width. The existence of trapping modes shows that in general a radiation condition for the waves at infinity is insufficient for uniqueness.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1951

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

REFERENCES

(1)Atkinson, F. V.On Sommerfeld's radiation condition. Phil. Mag. (7), 40 (1949), 645–51.Google Scholar
(2)Stokes, G. G.Report on recent researches in hydrodynamics. Brit. Ass. Rep. (1846), pp. 120.Google Scholar
(3)Havelock, T. H.Forced surface-waves on water. Phil. Mag. (7), 8 (1929), 569–76.Google Scholar
(4)von Koch, H.Sur les determinants infinis et les équations différentielles linéaires. Acta Math. 16 (1892), 217–95.CrossRefGoogle Scholar
(5)John, F.On the motion of floating bodies. II. Commun. Pure Appl. Math. 3 (1950), 153–8.CrossRefGoogle Scholar
(6)Ursell, F.Surface waves on deep water in the presence of a submerged circular cylinder. II. Proc. Cambridge Phil. Soc. 46 (1950), 153–8.CrossRefGoogle Scholar
(7)Watson, G. N.A treatise on the theory of Bessel functions, 2nd ed. (Cambridge, 1944).Google Scholar
(8)Whittaker, E. T. and Watson, G. N.A course of modern analysis, 2nd ed. (Cambridge, 1915).Google Scholar