Hostname: page-component-8448b6f56d-tj2md Total loading time: 0 Render date: 2024-04-16T23:20:11.205Z Has data issue: false hasContentIssue false

On step approximations for water-wave problems

Published online by Cambridge University Press:  26 April 2006

D. V. Evans
Affiliation:
School of Mathematics, University of Bristol, Bristol BS8 1TW, UK
C. M. Linton
Affiliation:
Department of Mathematical Sciences, Loughborough University of Technology, Leicestershire, LE11 3TU, UK

Abstract

The scattering of water waves by a varying bottom topography is considered using two-dimensional linear water-wave theory. A new approach is adopted in which the problem is first transformed into a uniform strip resulting in a variable free-surface boundary condition. This is then approximated by a finite number of sections on which the free-surface boundary condition is assumed to be constant. A transition matrix theory is developed which is used to relate the wave amplitudes at ±∞. The method is checked against examples for which the solution is known, or which can be computed by alternative means. Results show that the method provides a simple accurate technique for scattering problems of this type.

Type
Research Article
Copyright
© 1994 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

Chamberlain, P. G. 1993 Wave scattering over uneven depth using the mild-slope equation. Wave Motion 17, 267285.Google Scholar
Devillard, P., Dunlop, F. & Souillard, B. 1988 Localization of gravity waves on a channel with random bottom. J. Fluid Mech. 186, 521538.Google Scholar
Evans, D. V. 1972 The application of a new source potential to the problem of the transmission of water waves over a shelf of arbitrary profile. Proc. Camb. Phil. Soc. 71, 391410.Google Scholar
Evans, D. V. 1985 The solution of a class of boundary-value problems with smoothly varying boundary conditions. Q. J. Mech. Appl. Maths 38 (4), 521536.Google Scholar
Evans, D. V. 1990 The wide-spacing approximation applied to multiple scattering and sloshing problems. J. Fluid Mech. 210, 647658.Google Scholar
Fitz-Gerald, G. F. 1976 The reflexion of plane gravity waves travelling in water of variable depth. Phil. Trans. R. Soc. Lond. 34, 4989.Google Scholar
Hamilton, J. 1977 Differential equations for long-period gravity waves on fluid of rapidly varying depth. J. Fluid Mech. 83, 289310.Google Scholar
Henrici, P. 1974 Applied and Computational Complex Analysis, Vol 1. John Wiley and Sons.
Johnson, E. R. 1990 The low-frequency scattering of Kelvin waves by stepped topography. J. Fluid Mech. 215, 2344.Google Scholar
Keller, J. B. & Weitz, M. 1953 Reflection and transmission coefficients for waves entering or leaving an ice field. Commun. Pure Appl. Maths 6, 415417.Google Scholar
Kim, S. K., Liu, P. L.-F. & Liggett, J. A. 1983 Boundary integral equation solutions for solitary wave generation. Coastal Engng 7, 299317.Google Scholar
Lamb, H. 1932 Hydrodynamics, 6th edn. Cambridge University Press.
Levine, H. 1978 Unidirectional Wave Motions. North-Holland.
Linton, C. M. & Evans, D. V. 1992 Integral equations for a class of problems concerning obstacles in waveguides. J. Fluid Mech. 245, 349365.Google Scholar
Liu, P. L.-F. & Liggett, J. A. 1982 Applications of boundary element methods in problems of water waves. In Developments in Boundary Element Methods 2nd edn (ed. P. K. Banerjea & R. P. Shaw), Chap. 3, Applied Science Publishers.
Martin, P. A. 1984 Multiple scattering of surface water waves and the null-field method. Proc. 15th Symp. Naval Hydrodynamics, Hamburg, pp. 119132. National Academy Press.
Mei, C. C. & Black, J. L. 1969 Scattering of surface waves by rectangular obstacles in waters of finite depth. J. Fluid Mech. 38, 499511.Google Scholar
Miles, J. W. 1967 Surface-wave scattering matrix for a shelf. J. Fluid Mech. 28, 755767.Google Scholar
Mittra, R. & Lee, S. W. 1971 Analytical Techniques in the Theory of Guided Waves. Macmillan.
Nachbin, A. & Papanicolaou, G. C. 1992a Boundary element method for long-time water wave propagation over rapidly varying bottom topography.. Intl J. Numer. Meth. Fluids 14, 13471365.Google Scholar
Nachbin, A. & Papanicolaou, G. C. 1992b Water waves in shallow channels of rapidly varying depth.. J. Fluid Mech. 241, 311332.Google Scholar
Namba, M. & Fukushige, K. 1980 Application of the equivalent surface source method to the acoustics of duct systems with non-uniform wall impedance. J. Sound Vib. 73, 125146.Google Scholar
Newman, J. N. 1965 Propagation of water waves over an infinite step. J. Fluid Mech. 23, 399415.Google Scholar
O'Hare, T. J. & Davies, A. G. 1992 A new model for surface wave propagation over undulating topography. Coastal Engng 18, 251266.Google Scholar
Roseau, M. 1976 Asymptotic Wave Theory. North-Holland.
Ursell, F. 1947 The effect of a fixed vertical barrier on surface waves in deep water. Proc. Camb. Phil. Soc. 43, 364382.Google Scholar
Wehausen, J. N. & Laitone, E. V. 1960 Surface Waves. Handbuch der Physik. Springer.
Weitz, M. & Keller, J. B. 1950 Reflection of water waves from floating ice in water of finite depth. Commun. Pure Appl. Maths 3, 305318.Google Scholar
Yeung, R. W. 1975 A hybrid integral equation method for time-harmonic free surface flow. In Proc. 1st Intl Conf. on Num. Ship Hydrodynamics, pp. 581607.