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dc.contributor.authorBuza, G
dc.contributor.authorPage, J
dc.contributor.authorKerswell, RR
dc.date.accessioned2022-03-10T00:30:06Z
dc.date.available2022-03-10T00:30:06Z
dc.date.issued2022
dc.identifier.issn0022-1120
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/334822
dc.description.abstractThe recently-discovered centre-mode instability of rectilinear viscoelastic shear flow (Garg et al. Phy. Rev. Lett. 121, 024502, 2018) has offered an explanation for the origin of elasto-inertial turbulence (EIT) which occurs at lower Weissenberg ($Wi$) numbers. In support of this, we show using weakly nonlinear analysis that the subcriticality found in Page et al. (Phys. Rev. Lett. 125, 154501, 2020) is generic across the neutral curve with the instability only becoming supercritical at low Reynolds ($Re$) numbers and high $Wi$. We demonstrate that the instability can be viewed as purely elastic in origin even for $Re=O(10^3)$, rather than `elasto-inertial', as the underlying shear does not energise the instability. It is also found that the introduction of a realistic maximum polymer extension length, $L_{max}$, in the FENE-P model moves the neutral curve closer to the inertialess $Re=0$ limit at a fixed ratio of solvent-to-solution viscosities, $\beta$. In the dilute limit ($\beta \rightarrow 1$) with $L_{max} =O(100)$, the linear instability can brought down to more physically-relevant $Wi\gtrsim 110$ at $\beta=0.98$, compared with the threshold $Wi=O(10^3)$ at $\beta=0.994$ reported recently by Khalid et al. (arXiv: 2103.06794) for an Oldroyd-B fluid. Again the instability is subcritical implying that inertialess rectilinear viscoelastic shear flow is nonlinearly unstable - i.e. unstable to finite amplitude disturbances - for even lower $Wi$.
dc.publisherCambridge University Press (CUP)
dc.rightsAttribution-NonCommercial-NoDerivatives 4.0 International
dc.rights.urihttps://creativecommons.org/licenses/by-nc-nd/4.0/
dc.subjectphysics.flu-dyn
dc.subjectphysics.flu-dyn
dc.titleWeakly nonlinear analysis of the viscoelastic instability in channel flow for finite and vanishing Reynolds numbers
dc.typeArticle
dc.publisher.departmentDepartment of Applied Mathematics And Theoretical Physics
dc.date.updated2022-03-08T09:06:29Z
prism.publicationNameJournal of Fluid Mechanics
dc.identifier.doi10.17863/CAM.82256
dcterms.dateAccepted2022-03-07
rioxxterms.versionofrecord10.1017/jfm.2022.222
rioxxterms.versionAM
dc.contributor.orcidBuza, G [0000-0003-2009-705X]
dc.identifier.eissn1469-7645
rioxxterms.typeJournal Article/Review
cam.issuedOnline2022-04-08
cam.orpheus.successWed May 25 11:13:20 BST 2022 - Embargo updated
cam.orpheus.counter4
cam.depositDate2022-03-08
pubs.licence-identifierapollo-deposit-licence-2-1
pubs.licence-display-nameApollo Repository Deposit Licence Agreement
rioxxterms.freetoread.startdate2022-10-08


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