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On nonlinear wave envelopes of permanent form near a caustic

Published online by Cambridge University Press:  26 April 2006

T. R. Akylas
Affiliation:
Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
T.-J. Kung
Affiliation:
Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA

Abstract

In the vicinity of a caustic of a dispersive wave system, where the group velocity is stationary and hence dispersive effects are relatively weak, the nonlinear Schrödinger equation (NLS) breaks down, and the propagation of the envelope of a finiteamplitude wavepacket is governed by a modified nonlinear Schrödinger equation (MNLS). On the basis of the MNLS, a search for wave envelopes of permanent form is made near a caustic. It is shown that possible solitary wave envelopes satisfy a nonlinear eigenvalue problem. Numerical evidence is presented of symmetric, double-hump solitary-wave solutions. Also, a variety of periodic envelopes are computed. These findings are discussed in connection with previous analytical and numerical work.

Type
Research Article
Copyright
© 1990 Cambridge University Press

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References

Akylas, T. R. 1987 Unsteady and nonlinear effects near the cusp lines of the Kelvin ship-wave pattern. J. Fluid Mech. 175, 333342.Google Scholar
Brown, E. D., Buchsbaum, S. B., Hall, R. E., Penhune, J. P., Schmitt, K. F., Watson, K. M. & Wyatt, D. C. 1989 Observations of a nonlinear solitary wavepacket in the Kelvin wake of a ship. J. Fluid Mech. 204, 263293.Google Scholar
Bryant, P. J. 1984 Oblique wave groups in deep water. J. Fluid Mech. 146, 120.Google Scholar
Eckart, C. 1961 Internal waves in the ocean. Phys. Fluids 4, 791799.Google Scholar
Hui, W. H. & Hamilton, J. 1979 Exact solutions of a three-dimensional nonlinear Schrödinger equation applied to gravity waves. J. Fluid Mech. 93, 117133.Google Scholar
Jang, P. S. & Benney, D. J. 1981 Solitary envelope waves associated with Eckart resonance in stratified shear flows. Tech. Rep. DT-8167-1. Dynamics Technology, Inc., Torrance, CA.Google Scholar
Keller, H. B. 1977 Numerical solution of bifurcation and nonlinear eigenvalue problems. In Applications of Bifurcation Theory (ed. P. H. Rabinowitz), p. 359. Academic.
Kung, T.-J. 1989 A model for ship-generated nonlinear wave groups. Ph.D. thesis, Department of Mechanical Engineering, MIT.
Lichter, S. & Chen, J. 1987 Subharmonic resonance of nonlinear cross-waves. J. Fluid Mech. 183, 451465.Google Scholar
Lighthill, M. J. 1978 Waves in Fluids. Cambridge University Press.
Miles, J. & Becker, J. 1988 Parametrically excit ed. progressive cross-waves. J. Fluid Mech. 186, 129146.Google Scholar
Segur, H. & Kruskal, M. D. 1987 Nonexistence of small-amplitude breather solutions in 4 theory. Phys. Rev. Lett. 58, 747750.Google Scholar
Whitham, G. B. 1974 Linear and Nonlinear Waves. Wiley-Interscience.