dc.contributor.author Ball, Thomasina en dc.contributor.author Huppert, Herbert en dc.contributor.author Lister, John en dc.contributor.author Neufeld, Jerome en dc.date.accessioned 2017-07-05T11:46:59Z dc.date.available 2017-07-05T11:46:59Z dc.date.issued 2017-06-01 en dc.identifier.issn 0022-1120 dc.identifier.uri https://www.repository.cam.ac.uk/handle/1810/265188 dc.description.abstract The equilibration time in response to a change in flux from Q to $\Lambda$Q after an injection period applied to either a low-Reynolds-number gravity current or one propagating through a porous medium, in both axisymmetric and one-dimensional geometries, is shown to be of the form $\tau$ = Tf($\Lambda$) , independent of all the remaining physical parameters. Numerical solutions are used to investigate f($\Lambda$) for each of these situations and compare very well with experimental results in the case of an axisymmetric current propagating over a rigid horizontal boundary. Analysis of the relaxation towards self-similarity provides an illuminating connection between the excess (deficit) volume from early times and an asymptotically equivalent shift in time origin, and hence a good quantitative estimate of $\tau$ . The case of $\Lambda$ = 0 equilibration after ceasing injection at time T is a singular limit. Extensions to high-Reynolds-number currents and to the case of a constant-volume release followed by constant-flux injection are discussed briefly. dc.language eng en dc.language.iso en en dc.publisher Cambridge University Press dc.title The relaxation time for viscous and porous gravity currents following a change in flux en dc.type Article prism.endingPage 342 prism.publicationDate 2017 en prism.publicationName Journal of Fluid Mechanics en prism.startingPage 330 prism.volume 821 en dc.identifier.doi 10.17863/CAM.11244 dcterms.dateAccepted 2017-03-27 en rioxxterms.versionofrecord 10.1017/jfm.2017.243 en rioxxterms.version AM en rioxxterms.licenseref.uri http://www.rioxx.net/licenses/all-rights-reserved en rioxxterms.licenseref.startdate 2017-06-01 en dc.contributor.orcid Ball, Thomasina [0000-0001-8547-0586] dc.contributor.orcid Neufeld, Jerome [0000-0002-3284-5169] dc.identifier.eissn 1469-7645 rioxxterms.type Journal Article/Review en cam.issuedOnline 2017-05-24 en rioxxterms.freetoread.startdate 2017-11-24
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