A coupled-mode technique for wave-current interaction in variable bathymetry regions

Belibassakis, KA; Athanassoulis, GA

dc.contributor.author	Belibassakis, KA	en
dc.contributor.author	Athanassoulis, GA	en
dc.date.accessioned	2014-03-01T02:49:41Z
dc.date.available	2014-03-01T02:49:41Z
dc.date.issued	2004	en
dc.identifier.issn	10986189	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/34691
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-23844444908&partnerID=40&md5=bf3b4f54fb4e936bfaab0c74c8ad4d24	en
dc.subject	Coupled-modes	en
dc.subject	Scattering of waves by current	en
dc.subject	Variable bathymetry	en
dc.subject	Wave-current interaction	en
dc.subject.other	Approximation theory	en
dc.subject.other	Bathymetry	en
dc.subject.other	Boundary conditions	en
dc.subject.other	Electromagnetic wave scattering	en
dc.subject.other	Ocean currents	en
dc.subject.other	Problem solving	en
dc.subject.other	Vortex flow	en
dc.subject.other	Coupled-modes	en
dc.subject.other	Scattering of waves by current	en
dc.subject.other	Variable bathymetry	en
dc.subject.other	Wave-current interactions	en
dc.subject.other	Water waves	en
dc.title	A coupled-mode technique for wave-current interaction in variable bathymetry regions	en
heal.type	conferenceItem	en
heal.publicationDate	2004	en
heal.abstract	A coupled-mode technique for wave-current interaction is presented, with application to the problem of wave scattering by steady currents in variable bathymetry regions, and current variations on various scales. We consider obliquely incident waves on a horizontally non-homogeneous current in a variable-depth strip, which is characterized by straight and parallel bottom contours. The flow associated with the current is assumed to be parallel to the bottom contours (along-axis current) and it is considered to be known. In a finite subregion containing the bottom irregularity we assume an arbitrary horizontal current structure. Outside this region, the current is assumed to be uniform (or zero). At a first-order of approximation the wave flow is assumed to be irrotational, i.e. the vorticity of the total field is the same with the vorticity associated with the current. Then, restricting ourselves to linear, monochromatic (harmonic) waves of absolute frequency co, the wave potential, including the scattering effect by the current, is obtained as a solution to the modified Helmholtz equation, subject to the free-surface boundary condition formulated with respect to the intrinsic frequency, the bottom boundary condition, and the conditions at infinity. Based on an appropriate variational principle, in conjunction with a rapidly-convergent local-mode series expansion of the wave field in a finite subregion containing the current variation and the bottom irregularity, a coupled-mode system is obtained that can be considered as a generalization of the one derived by Athanassoulis & Belibassakis (1999). The present approach can be considered as an extension of the works by Smith (1983, 1987), and some of its main features are that it can be further elaborated to treat lateral discontinuities (e.g. vertical vortex sheets) and more general vertical current profiles with cross-jet component, and to include the effects of weak nonlinearity. Copyright © 2004 by The International Society of Offshore and Polar Engineers.	en
heal.journalName	Proceedings of the International Offshore and Polar Engineering Conference	en
dc.identifier.spage	226	en
dc.identifier.epage	233	en