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![]() |
刊名 | PHYSICS OF THE EARTH AND PLANETARY INTERIORS
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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. |
入库方式: OAI收割
来源:上海天文台
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