Hostname: page-component-77c89778f8-fv566 Total loading time: 0 Render date: 2024-07-19T16:54:05.376Z Has data issue: false hasContentIssue false

Instability and breaking of a solitary wave

Published online by Cambridge University Press:  21 April 2006

M. Tanaka
Affiliation:
School of Mathematics, University of Bristol, University Walk, Bristol BS8 1TW, UK
J. W. Dold
Affiliation:
School of Mathematics, University of Bristol, University Walk, Bristol BS8 1TW, UK
M. Lewy
Affiliation:
School of Mathematics, University of Bristol, University Walk, Bristol BS8 1TW, UK
D. H. Peregrine
Affiliation:
School of Mathematics, University of Bristol, University Walk, Bristol BS8 1TW, UK

Abstract

The result of a linear stability calculation of solitary waves which propagate steadily along the free surface of a liquid layer of constant depth is examined numerically by employing a time-stepping scheme based on a boundary-integral method. The initial’ growth rate that is found for sufficiently small perturbations agrees well with the growth rate expected from the linear stability calculation. In calculating the later ‘nonlinear’ stage of the instability, it is found that two distinct types of long-time evolution are possible. These depend only on the sign of the unstable normal-mode perturbation that is superimposed initially on the steady wave. The growth of the perturbation ultimately leads to breaking for one sign. Unexpectedly, for the opposite sign, there is a monotonic decrease in the total height of the wave. In this latter case there is a smooth evolution to a stable solitary wave of lesser amplitude but very nearly the same energy.

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

Dold, J. W. & Peregrine D. H. 1986 An efficient boundary-integral method for steep unsteady water waves. In Numerical Methods for Fluid Dynamics II (ed. K. W. Morton & M. J. Baines), pp. 671679. Clarendon.
Longuet-Higgins, M. S. 1984 On the stability of steep gravity waves. Proc. R. Soc. Lond. A 396, 269280.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. R. Soc. Lond. A 364, 128.Google Scholar
New, A. L. 1983 On the breaking of water waves. Ph.D. dissertation, University of Bristol.
Saffman, P. G. 1985 The superharmonic instability of finite-amplitude water waves. J. Fluid Mech. 159, 169174.Google Scholar
Tanaka, M. 1983 The stability of steep gravity waves. J. Phys. Soc. Japan 52, 30473055.Google Scholar
Tanaka, M. 1985 The stability of sleep gravity waves. Part 2. J. Fluid Mech. 156, 281289.Google Scholar
Tanaka, M. 1986 The stability of solitary waves. Phys. Fluids 29, 650655.Google Scholar
Zufiria, J. A. & Saffman, P. G. 1986 The superharmonic instability of finite-amplitude surface waves on water of finite depth. Stud. Appl. Maths 74, 259266.Google Scholar