中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Simulations of fluid motion in ellipsoidal planetary cores driven by longitudinal libration

文献类型:期刊论文

作者Chan, Kit H.1; Liao, Xinhao2; Zhang, Keke3
刊名PHYSICS OF THE EARTH AND PLANETARY INTERIORS
出版日期2011-08-01
卷号187期号:3-4页码:391-403
关键词Planetary fluid cores Ellipsoid Longitudinal libration
英文摘要Deformed 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 epsilon = root 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. (C) 2011 Elsevier B.V. All rights reserved.
WOS标题词Science & Technology ; Physical Sciences
类目[WOS]Geochemistry & Geophysics
研究领域[WOS]Geochemistry & Geophysics
关键词[WOS]ROTATING SPHERICAL CAVITY ; FINITE-ELEMENT-METHOD ; INERTIAL OSCILLATIONS ; MOLTEN CORE ; FLOWS ; CONVECTION
收录类别SCI
语种英语
WOS记录号WOS:000296207900027
源URL[http://119.78.226.72/handle/331011/26402]  
专题上海天文台_天文地球动力学研究中心
作者单位1.Univ Hong Kong, Dept Math, Pokfulam, Hong Kong, Peoples R China
2.Chinese Acad Sci, Shanghai Astron Observ, Shanghai 200030, Peoples R China
3.Univ Exeter, Dept Math Sci, Exeter EX4 4QE, Devon, England
推荐引用方式
GB/T 7714
Chan, Kit H.,Liao, Xinhao,Zhang, Keke. Simulations of fluid motion in ellipsoidal planetary cores driven by longitudinal libration[J]. PHYSICS OF THE EARTH AND PLANETARY INTERIORS,2011,187(3-4):391-403.
APA Chan, Kit H.,Liao, Xinhao,&Zhang, Keke.(2011).Simulations of fluid motion in ellipsoidal planetary cores driven by longitudinal libration.PHYSICS OF THE EARTH AND PLANETARY INTERIORS,187(3-4),391-403.
MLA Chan, Kit H.,et al."Simulations of fluid motion in ellipsoidal planetary cores driven by longitudinal libration".PHYSICS OF THE EARTH AND PLANETARY INTERIORS 187.3-4(2011):391-403.

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来源:上海天文台

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