Publication
A numerical study of steady and unsteady viscoelastic flow past bounded cylinders
| dc.contributor.author | Oliveira, Paulo J. | |
| dc.contributor.author | Miranda, Amílcar I. P. | pt |
| dc.date.accessioned | 2010-04-28T10:07:17Z | |
| dc.date.available | 2010-04-28T10:07:17Z | |
| dc.date.issued | 2005 | |
| dc.description.abstract | We consider two-dimensional, inertia-free, flow of a constant-viscosity viscoelastic fluid obeying the FENE-CR equation past a cylinder placed symmetrically in a channel, with a blockage ratio of 0.5. Through numerical simulations we show that the flow becomes unsteady when the Deborah number (using the usual definition) is greater than De≈1.3, for an extensibility parameter of the model of L2 = 144. The transition from steady to unsteady flow is characterised by a small pulsating recirculation zone of size approximately equal to 0.15 cylinder radius attached to the downstream face of the cylinder. There is also a rise in drag coefficient, which shows a sinusoidal variation with time. The results suggest a possible triggering mechanism leading to the steady three-dimensional Gortler-type vortical structures, which have been observed in experiments of the flow of a viscoelastic fluid around cylinders. The results reveal that the reason for failure of the search for steady numerical solutions at relatively high Deborah numbers is that the two-dimensional flow separates and eventually becomes unsteady. For a lower extensibility parameter, L2 = 100, a similar recirculation is formed given rise to a small standing eddy behind the cylinder which becomes unsteady and pulsates in time for Deborah numbers larger than De≈4.0–4.5. | pt |
| dc.identifier.uri | http://hdl.handle.net/10400.6/607 | |
| dc.language | eng | |
| dc.subject | Cylinder | pt |
| dc.subject | Viscoelastic | pt |
| dc.subject | FENE-CR | pt |
| dc.subject | Unsteady flow | pt |
| dc.subject | Elastic instability | pt |
| dc.subject | Flow separation at Re=0 | pt |
| dc.title | A numerical study of steady and unsteady viscoelastic flow past bounded cylinders | pt |
| dc.type | journal article | |
| dspace.entity.type | Publication | |
| oaire.citation.issue | Vol. 127, No.1 , pp. 51-66. | pt |
| oaire.citation.title | Journal of Non-Newtonian Fluid Mechanics | pt |
| person.familyName | Oliveira | |
| person.givenName | Paulo J. | |
| person.identifier.ciencia-id | 7A15-7012-C5DF | |
| person.identifier.orcid | 0000-0001-9843-7558 | |
| person.identifier.rid | A-4638-2009 | |
| person.identifier.scopus-author-id | 24280605700 | |
| rcaap.rights | openAccess | |
| rcaap.type | article | pt |
| relation.isAuthorOfPublication | f4a5da68-73fb-4a8b-9418-669d76d75f39 | |
| relation.isAuthorOfPublication.latestForDiscovery | f4a5da68-73fb-4a8b-9418-669d76d75f39 |
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