Hostname: page-component-77c89778f8-swr86 Total loading time: 0 Render date: 2024-07-20T07:48:00.746Z Has data issue: false hasContentIssue false

Refraction of finite-amplitude water waves: deep-water waves approaching circular caustics

Published online by Cambridge University Press:  20 April 2006

D. H. Peregrine
Affiliation:
School of Mathematics, University of Bristol

Abstract

The ‘numerically exact’ properties of plane periodic deep-water waves are used in a slowly-varying-wave approximation for a steady axisymmetric wave field. The linear ‘ray’ theory for such a wave field corresponds to waves approaching a circular caustic. A parameter, C, characterizes each solution. If C is smaller than 20 the wave behaviour is dominated by the convergence of wave energy and waves are expected to break. Comparison with experiment for C = 0 indicates that breaking may be accurately predicted. If C is greater than 50 then the waves propagate closer to the caustic and, since it is of Peregrine & Smith's (1979) type R, it is likely that the waves do not break. These solutions show that wave action does not flow along the straight lines of the linear rays.

Type
Research Article
Copyright
© 1981 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

Abramowitz, M. & Stegun, I. A. 1964 Handbook of Mathematical Functions. Washington: National Bureau of Standards.
Cokelet, E. D. 1977 Steep gravity waves in water of arbitrary uniform depth. Phil. Trans. Roy. Soc. A 286, 183230.Google Scholar
Crapper, G. D. 1979 Energy and momentum integrals for progressive capillary — gravity waves. J. Fluid Mech. 94, 1324.Google Scholar
Hayes, W. D. 1973 Group velocity and nonlinear dispersive wave propagation. Proc. Roy. Soc. A 332, 199221.Google Scholar
Longuet-Higgins, M. S. 1975 Integral properties of periodic gravity waves of finite amplitude. Proc. Roy. Soc. A 342, 157174.Google Scholar
Longuet-Higgins, M. S. 1978 The instabilities of gravity waves of finite amplitude in deep water. II. Subharmonics. Proc. Roy. Soc. A 360, 489505.Google Scholar
Longuet-Higgins, M. S. & Cokelet, E. D. 1978 The deformation of steep surface waves on water. II. Growth of normal mode instabilities. Proc. Roy. Soc. A 364, 128.Google Scholar
Peregrine, D. H. & Smith, R. 1979 Nonlinear effects upon waves near caustics. Phil. Trans. Roy. Soc. A 292, 341370.Google Scholar
Peregrine, D. H. & Thomas, G. P. 1979 Finite-amplitude deep-water waves on currents. Phil. Trans. Roy. Soc. A 292, 371390.Google Scholar
Phillips, O. M. 1966 The Dynamics of the Upper Ocean. Cambridge University Press.
Ryrie, S. & Peregrine, D. H. 1981 Refraction of finite-amplitude water waves obliquely incident to a uniform beach. (Submitted for publication.)
Stiassnie, M. & Peregrine, D. H. 1979 On averaged equations for finite-amplitude water waves. J. Fluid Mech. 94, 401405.Google Scholar
Stiassnie, M. & Peregrine, D. H. 1980 Shoaling of finite-amplitude surface waves on water of slowly-varying depth. J. Fluid Mech. 97, 783805.Google Scholar
Van Dorn, W. G. & Pazan, S. E. 1975 Laboratory investigation of wave breaking, Part II: Deep water waves. A.O.E.L. Rep. no. 71, SIO Ref. no. 75–21. Scripps Institution of Oceanog., Univ. of Calif. San Diego.Google Scholar
Whitham, G. B. 1974 Lincur and Non-Linear Waves. Wiley-Interscience.