Gas transfer under breaking waves: Experiments and an improved vorticity-based model

Tsoukala, VK; Moutzouris, CI

dc.contributor.author	Tsoukala, VK	en
dc.contributor.author	Moutzouris, CI	en
dc.date.accessioned	2014-03-01T01:28:30Z
dc.date.available	2014-03-01T01:28:30Z
dc.date.issued	2008	en
dc.identifier.issn	0992-7689	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/18856
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-49149102429&partnerID=40&md5=fbed28fe0eea4c53d98f532862d8281f	en
dc.subject	oceanography : general	en
dc.subject	marine pollution	en
dc.subject	oceanography : physical	en
dc.subject	air-sea interactions	en
dc.subject	space plasma physics	en
dc.subject	laboratory studies	en
dc.subject.classification	Astronomy & Astrophysics	en
dc.subject.classification	Geosciences, Multidisciplinary	en
dc.subject.classification	Meteorology & Atmospheric Sciences	en
dc.subject.other	breaking wave	en
dc.subject.other	breakwater	en
dc.subject.other	experimental study	en
dc.subject.other	gas transport	en
dc.subject.other	harbor	en
dc.subject.other	modeling	en
dc.subject.other	numerical method	en
dc.subject.other	vorticity	en
dc.subject.other	wind forcing	en
dc.subject.other	Benelux	en
dc.subject.other	Eurasia	en
dc.subject.other	Europe	en
dc.subject.other	Greece	en
dc.subject.other	Netherlands	en
dc.subject.other	Southern Europe	en
dc.subject.other	Western Europe	en
dc.title	Gas transfer under breaking waves: Experiments and an improved vorticity-based model	en
heal.type	journalArticle	en
heal.language	English	en
heal.publicationDate	2008	en
heal.abstract	In the present paper a modified vorticity-based model for gas transfer under breaking waves in the absence of significant wind forcing is presented. A theoretically valid and practically applicable mathematical expression is suggested for the assessment of the oxygen transfer coefficient in the area of wave-breaking. The proposed model is based on the theory of surface renewal that expresses the oxygen transfer coefficient as a function of both the wave vorticity and the Reynolds wave number for breaking waves. Experimental data were collected in wave flumes of various scales: a) small-scale experiments were carried out using both a sloping beach and a rubble-mound breakwater in the wave flume of the Laboratory of Harbor Works, NTUA, Greece; b) large-scale experiments were carried out with a sloping beach in the wind-wave flume of Delft Hydraulics, the Netherlands, and with a three-layer rubble mound breakwater in the Schneideberg Wave Flume of the Franzius Institute, University of Hannover, Germany. The experimental data acquired from both the small- and large-scale experiments were in good agreement with the proposed model. Although the apparent transfer coefficients from the large-scale experiments were lower than those determined from the small-scale experiments, the actual oxygen transfer coefficients, as calculated using a discretized form of the transport equation, are in the same order of magnitude for both the small- and large-scale experiments. The validity of the proposed model is compared to experimental results from other researchers. Although the results are encouraging, additional research is needed, to incorporate the influence of bubble mediated gas exchange, before these results are used for an environmental friendly design of harbor works, or for projects involving waste disposal at sea.	en
heal.publisher	COPERNICUS PUBLICATIONS	en
heal.journalName	Annales Geophysicae	en
dc.identifier.isi	ISI:000258687200005	en
dc.identifier.volume	26	en
dc.identifier.issue	8	en
dc.identifier.spage	2131	en
dc.identifier.epage	2142	en