File Download

There are no files associated with this item.

  Links for fulltext
     (May Require Subscription)
Supplementary

Article: Simulations of fluid motion in ellipsoidal planetary cores driven by longitudinal libration

TitleSimulations of fluid motion in ellipsoidal planetary cores driven by longitudinal libration
Authors
KeywordsEllipsoid
Longitudinal libration
Planetary fluid cores
Issue Date2011
PublisherElsevier BV. The Journal's web site is located at http://www.elsevier.com/locate/pepi
Citation
Physics Of The Earth And Planetary Interiors, 2011, v. 187 n. 3-4, p. 391-403 How to Cite?
AbstractDeformed by tidal forces, the cavity of a planetary fluid core may be in the shape of a biaxial ellipsoid x 2/a 2+y 2/b 2+z 2/a 2=1, where a and b are two different semi-axes and z is in the direction of rotation. Gravitational interaction between a planet and its parent star exerts an axial torque on the planet and forces its longitudinal libration, a periodic variation of its angular velocity around its rotating axis. Longitudinal libration drives fluid motion in the planetary core via both viscous and topographic coupling between the mantle and fluid. For an arbitrary size of the equatorial eccentricity E=√a 2-b 2/a, direct numerical simulation of the fully nonlinear problem is carried out using an EBE (Element-By-Element) finite element method. It is shown that fluid motion driven by longitudinal libration vacillates between two different phases: a prograde phase when the planet's rotation speeds up and a retrograde phase when it slows down. For weak longitudinal libration, the fluid motion is laminar without exhibiting noticeable differences between the two phases and a multi-layered, time-independent, nearly geostrophic mean flow can be generated and maintained by longitudinal libration in a biaxial or triaxial ellipsoidal cavity. For strong slow libration, there are profound differences between the two different phases: the retrograde phase is usually marked by fluid motion with instabilities and complex spatial structure while in the prograde phase the flow is still largely laminar. © 2011 Elsevier B.V.
Persistent Identifierhttp://hdl.handle.net/10722/135161
ISSN
2015 Impact Factor: 2.605
2015 SCImago Journal Rankings: 2.140
ISI Accession Number ID
Funding AgencyGrant Number
Hong Kong RGC700308
NSFC10633030
CAS
UK NERC
Leverhulme Trust
STFC
Funding Information:

We thank J. Noir and J. Aurnou for helpful discussions on the problem. K.H.C. is supported by Hong Kong RGC Grant/700308, X.L. is supported by NSFC/10633030 and CAS grants and K.Z. is supported by UK NERC, Leverhulme Trust and STFC grants. The parallel computation is supported by Shanghai Supercomputer Center (SSC).

References

 

DC FieldValueLanguage
dc.contributor.authorChan, KHen_HK
dc.contributor.authorLiao, Xen_HK
dc.contributor.authorZhang, Ken_HK
dc.date.accessioned2011-07-27T01:29:10Z-
dc.date.available2011-07-27T01:29:10Z-
dc.date.issued2011en_HK
dc.identifier.citationPhysics Of The Earth And Planetary Interiors, 2011, v. 187 n. 3-4, p. 391-403en_HK
dc.identifier.issn0031-9201en_HK
dc.identifier.urihttp://hdl.handle.net/10722/135161-
dc.description.abstractDeformed by tidal forces, the cavity of a planetary fluid core may be in the shape of a biaxial ellipsoid x 2/a 2+y 2/b 2+z 2/a 2=1, where a and b are two different semi-axes and z is in the direction of rotation. Gravitational interaction between a planet and its parent star exerts an axial torque on the planet and forces its longitudinal libration, a periodic variation of its angular velocity around its rotating axis. Longitudinal libration drives fluid motion in the planetary core via both viscous and topographic coupling between the mantle and fluid. For an arbitrary size of the equatorial eccentricity E=√a 2-b 2/a, direct numerical simulation of the fully nonlinear problem is carried out using an EBE (Element-By-Element) finite element method. It is shown that fluid motion driven by longitudinal libration vacillates between two different phases: a prograde phase when the planet's rotation speeds up and a retrograde phase when it slows down. For weak longitudinal libration, the fluid motion is laminar without exhibiting noticeable differences between the two phases and a multi-layered, time-independent, nearly geostrophic mean flow can be generated and maintained by longitudinal libration in a biaxial or triaxial ellipsoidal cavity. For strong slow libration, there are profound differences between the two different phases: the retrograde phase is usually marked by fluid motion with instabilities and complex spatial structure while in the prograde phase the flow is still largely laminar. © 2011 Elsevier B.V.en_HK
dc.languageengen_US
dc.publisherElsevier BV. The Journal's web site is located at http://www.elsevier.com/locate/pepien_HK
dc.relation.ispartofPhysics of the Earth and Planetary Interiorsen_HK
dc.subjectEllipsoiden_HK
dc.subjectLongitudinal librationen_HK
dc.subjectPlanetary fluid coresen_HK
dc.titleSimulations of fluid motion in ellipsoidal planetary cores driven by longitudinal librationen_HK
dc.typeArticleen_HK
dc.identifier.emailChan, KH:mkhchan@hku.hken_HK
dc.identifier.authorityChan, KH=rp00664en_HK
dc.description.naturelink_to_subscribed_fulltext-
dc.identifier.doi10.1016/j.pepi.2011.04.015en_HK
dc.identifier.scopuseid_2-s2.0-80053198413en_HK
dc.identifier.hkuros188099en_US
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-80053198413&selection=ref&src=s&origin=recordpageen_HK
dc.identifier.volume187en_HK
dc.identifier.issue3-4en_HK
dc.identifier.spage391en_HK
dc.identifier.epage403en_HK
dc.identifier.eissn1872-7395-
dc.identifier.isiWOS:000296207900027-
dc.publisher.placeNetherlandsen_HK
dc.identifier.scopusauthoridChan, KH=7406033542en_HK
dc.identifier.scopusauthoridLiao, X=7202134147en_HK
dc.identifier.scopusauthoridZhang, K=7404451892en_HK
dc.identifier.citeulike9370654-

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats