Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-18T18:18:27.778Z Has data issue: false hasContentIssue false

Dissipative effects on the resonant flow of a stratified fluid over topography

Published online by Cambridge University Press:  21 April 2006

N. F. Smyth
Affiliation:
Department of Mathematics, University of Wollongong, P.O. Box 1144, Wollongong, NSW, 2500, Australia

Abstract

The effect of dissipation on the flow of a stratified fluid over topography is considered in the weakly nonlinear, long-wave limit for the case when the flow is near resonance, i.e. the basic flow speed is close to a linear long-wave speed for one of the long-wave modes. The two types of dissipation considered are the dissipation due to viscosity acting in boundary layers and/or interfaces and the dissipation due to viscosity acting in the fluid as a whole. The effect of changing bottom topography on the flow produced by a force moving at a resonant velocity is also considered. In this case, the resonant condition is that the force velocity is close to a linear long-wave velocity for one of the long-wave modes. It is found that in most cases, these extra effects result in the formation of a steady state, in contrast to the flow without these effects, which remains unsteady for all time. The flow resulting under the action of boundary-layer dissipation is compared with recent experimental results.

Type
Research Article
Copyright
© 1988 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

Akylas T. R. 1984 On the excitation of long nonlinear water waves by a moving pressure distribution. J. Fluid Mech. 141, 455466.Google Scholar
Baines P. G. 1984 A unified description of two-layer flow over topography. J. Fluid Mech. 146, 127167.Google Scholar
Cole S. L. 1985 Transient waves produced by flow past a bump. Wave Motion 7, 579587.Google Scholar
Fornberg, B. & Whitham G. B. 1978 A numerical and theoretical study of certain nonlinear wave phenomena. Phil. Trans. R. Soc. Lond. A 289, 373404.Google Scholar
Grimshaw R. H. J. 1983 Solitary waves in density stratified fluids. In Nonlinear Deformation Waves, IUTAM Symp., Tallinn 1982 (ed. U. Nigul & J. Engelbrecht), pp. 431–447. Springer.
Grimshaw, R. H. J. & Smyth N. F. 1986 Resonant flow of a stratified fluid over topography. J. Fluid Mech. 169, 429464.Google Scholar
Hammack, J. L. & Segur H. 1974 The Korteweg-de Vries equation and water waves. Part 2. Comparison with experiments. J. Fluid Mech. 65, 289314.Google Scholar
Johnson R. S. 1970 A nonlinear equation incorporating damping and dispersion. J. Fluid Mech. 42, 4960.Google Scholar
Karpman V. I. 1979 Soliton evolution in the presence of perturbation. Physica Scr. 20, 462478.Google Scholar
Keulegan G. H. 1948 Gradual damping of solitary waves J. Res. Natn. Bur. Stand. 40, 487498.Google Scholar
Knickerbocker, C. J. & Newell A. C. 1980 Shelves and the Korteweg–de Vries equation. J. Fluid Mech. 98, 803818.Google Scholar
Lee S.-J. 1985 Generation of long water waves by moving disturbances. Ph.D. thesis, California Institute of Technology.
Leone C., Segur, H. & Hammack J. L. 1982 Viscous decay of long internal solitary waves. Phys. Fluids 25, 942944.Google Scholar
Melville, W. K. & Helfrich K. R. 1987 Transcritical two-layer flow over topography. J. Fluid Mech. 178, 3152.Google Scholar
Miles J. W. 1976 Korteweg–de Vries equation modified by viscosity. Phys. Fluids 19, 1063.Google Scholar
Ovstrovsky L. A. 1976 Short-wave asymptotics for weak shock waves and solitons in mechanics. Intl J. Nonlinear Mech. 11, 401416.Google Scholar
Smyth N. F. 1987 Modulation theory solution for resonant flow over topography Proc. R. Soc. Lond. A 409, 7997.Google Scholar
Weidman, P. & Maxworthy T. 1978 Experiments on strong interactions between solitary waves. J. Fluid Mech. 85, 417431.Google Scholar
Whitham G. B. 1974 Linear and Nonlinear Waves. Wiley.