A coupled-mode model for water wave scattering by horizontal, non-homogeneous current in general bottom topography

 
This item is provided by the institution :
Technological Educational Institute of Athens
Repository :
Ypatia - Institutional Repository
see the original item page
in the repository's web site and access all digital files if the item*
share




2011 (EN)
A coupled-mode model for water wave scattering by horizontal, non-homogeneous current in general bottom topography (EL)

Αθανασούλης, Γ. (EL)
Γεροστάθης, Θεόδωρος (EL)
Βελιβασάκης, Κ. (EL)

Τεχνολογικό Εκπαιδευτικό Ίδρυμα Αθήνας. Σχολή Τεχνολογικών Εφαρμογών. Τμήμα Ναυπηγών Μηχανικών Τ.Ε. (EL)

A coupled-mode model is developed for treating the wave–current–seabed interaction problem, with application to wave scattering by non-homogeneous, steady current over general bottom topography. The vertical distribution of the scattered wave potential is represented by a series of local vertical modes containing the propagating mode and all evanescent modes, plus additional terms accounting for the satisfaction of the free-surface and bottom boundary conditions. Using the above representation, in conjunction with unconstrained variational principle, an improved coupled system of differential equations on the horizontal plane, with respect to the modal amplitudes, is derived. In the case of small-amplitude waves, a linearised version of the above coupled-mode system is obtained, generalizing previous results by Athanassoulis and Belibassakis [J Fluid Mech 1999;389:275–301] for the propagation of small-amplitude water waves over variable bathymetry regions. Keeping only the propagating mode in the vertical expansion of the wave potential, the present system reduces to an one-equation model, that is shown to be compatible with mild-slope model concerning wave–current interaction over slowly varying topography, and in the case of no current it exactly reduces to the modified mild-slope equation. The present coupled-mode system is discretized on the horizontal plane by using second-order finite differences and numerically solved by iterations. Results are presented for various representative test cases demonstrating the usefulness of the model, as well as the importance of the first evanescent modes and the additional sloping-bottom mode when the bottom slope is not negligible. The analytical structure of the present model facilitates its extension to fully non-linear waves, and to wave scattering by currents with more general structure. (EN)

journalArticle

συνδυασμός τρόπων (EN)
Coupled modes (EN)
υποθαλάσσια αλληλεπίδραση κύματος-ρεύματος (EN)
Wave–current–seabed interaction (EN)

ΤΕΙ Αθήνας (EL)
Technological Educational Institute of Athens (EN)

Applied Ocean Research (EN)

English

2011-10

DOI:10.1016/j.apor.2011.05.004

N/A (EN)



*Institutions are responsible for keeping their URLs functional (digital file, item page in repository site)