Hostname: page-component-848d4c4894-xm8r8 Total loading time: 0 Render date: 2024-06-20T12:56:56.446Z Has data issue: false hasContentIssue false

Exact Floquet theory for waves over arbitrary periodic topographies

Published online by Cambridge University Press:  28 September 2012

Jie Yu*
Affiliation:
Department of Civil, Construction and Environmental Engineering, North Carolina State University, Raleigh, NC 27695-7908, USA
Louis N. Howard
Affiliation:
Department of Mathematics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
*
Email address for correspondence: jie_yu@ncsu.edu

Abstract

We consider linear waves propagating over periodic topographies of arbitrary amplitude and wave form, generalizing the method in Howard & Yu (J. Fluid Mech., vol. 593, 2007, pp. 209–234). By a judicious construction of a conformal map from the flow domain to a uniform strip, exact solutions of Floquet type can be developed in the mapped plane. These Floquet solutions, in an essentially analytical form, are analogous to the complete set of flat-bottom propagating and evanescent waves. Therefore they can be used as a basis for the solutions of boundary value problems involving a wavy topography with a constant mean water depth. Various concrete examples are given and quantitative results are discussed. Comparisons with experimental data are made, and qualitative agreement is achieved.

Type
Papers
Copyright
©2012 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

Ahlfors, L. 1953 Complex Analysis. McGraw-Hill.Google Scholar
Athanassoulis, G. A. & Belibassakis, K. A. 1999 A consistent coupled-mode theory for the propagation of small-amplitude water waves over variable bathymetry regions. J. Fluid Mech. 389, 275301.Google Scholar
Davies, A. G. 1982 The reflection of wave energy by undulations on the seabed. Dyn. Atmos. Oceans 6, 207232.Google Scholar
Devillard, P., Dunlop, F. & Souillard, B. 1988 Localization of gravity waves on a channel with a random bottom. J. Fluid Mech. 186, 521538.Google Scholar
Evans, D. V. & Linton, C. M. 1994 On step approximations for water-wave problems. J. Fluid Mech. 278, 229249.Google Scholar
Guazzelli, E., Rey, V. & Belzons, M. 1992 Higher-order Bragg reflection of gravity surface waves by periodic beds. J. Fluid Mech. 245, 301317.Google Scholar
Heathershaw, A. D. 1982 Seabed–wave resonance and sand bar growth. Nature 296, 343345.Google Scholar
Howard, L. N. & Yu, J. 2007 Normal modes of a rectangular tank with corrugated bottom. J. Fluid Mech. 593, 209234.Google Scholar
Jeffreys, H. & Jeffreys, B. S. 1950 Methods of Mathematical Physics, 2nd edn. Cambridge University Press.Google Scholar
Kirby, J. T. 1986 A general wave equation for waves over rippled beds. J. Fluid Mech. 162, 171186.Google Scholar
Magnus, W. & Winkler, S. 1979 Hill’s Equation. Dover.Google Scholar
Mattioli, F. 1990 Resonance reflection of a series of submerged breakwaters. Il Nuovo Cimento 13C, 823833.Google Scholar
Mei, C. C. 1985 Resonant reflection of surface water waves by periodic sandbars. J. Fluid Mech. 152, 315337.Google Scholar
Mei, C. C., Hara, T. & Yu, J. 2001 Longshore bars and Bragg resonance. In Geomorphological Fluid Mechanics (ed. Balmforth, N. & Provenzale, A.), Lecture Notes in Physics , vol. 582, chap. 20, pp. 500527. Springer.CrossRefGoogle Scholar
Nachbin, A. 1995 The localization length of randomly scattered water waves. J. Fluid Mech. 296, 353372.Google Scholar
Nachbin, A. & Papanicolaou, G. C. 1992 Water waves in shallow channels of rapidly varying depth. J. Fluid Mech. 241, 311332.Google Scholar
O’Hare, T. J. & Davies, A. G. 1992 A new model for surface wave propagation over undulating topography. Coast. Engng 18, 251266.Google Scholar
Porter, R. & Porter, D. 2003 Scattered and free waves over periodic beds. J. Fluid Mech. 483, 129163.CrossRefGoogle Scholar
Rey, V. 1992 Propagation and local behavior of normal incident gravity waves over varying topographies. Eur. J. Mech. B 11, 213232.Google Scholar
Whittaker, E. T. & Watson, G. N. 1927 A Course of Modern Analysis, 4th edn. Cambridge University Press.Google Scholar
Yu, J. & Howard, L. N. 2010 On higher order Bragg resonance of water waves by bottom corrugations. J. Fluid Mech. 659, 484504.Google Scholar
Yu, J. & Mei, C. C. 2000 Do longshore bars shelter the shore? J. Fluid Mech. 404, 251268.Google Scholar
Yu, J. & Zheng, G. 2012 Exact solutions for wave propagation over a patch of large bottom corrugations. J. Fluid Mech. (in press).Google Scholar
Zheng, G. 2011 Exact solutions for linear water wave scattering by a patch of finite amplitude periodic corrugations on a seabed. MSc thesis, Department of Civil, Construction and Environmental Engineering, North Carolina State University.Google Scholar