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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: [email protected]

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

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