The non-resonant response of fluid in a rapidly rotating sphere undergoing longitudinal libration
文献类型：期刊论文
| 作者 | Zhang, Keke1; Chan, Kit H.2; Liao, Xinhao3 ; Aurnou, Jonathan M.4
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| 刊名 | JOURNAL OF FLUID MECHANICS
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| 出版日期 | 2013-04-01 |
| 卷号 | 720页码:212-235 |
| 关键词 | geophysical and geological flows rotating flows |
| 英文摘要 | We investigate the problem of oscillatory flow of a homogeneous fluid with viscosity nu in a fluid-filled sphere of radius a that rotates rapidly about a fixed axis with angular velocity Omega(0) and that undergoes weak longitudinal libration with amplitude epsilon Omega(0) and frequency (omega) over cap Omega(0), where epsilon is the Poincare number with epsilon << 1 and (omega) over cap is dimensionless frequency with 0 < <(omega)over cap> < 2. Three different methods are employed in this investigation: (i) asymptotic analysis at small Ekman numbers E defined as E = nu/(a(2)Omega(0)); (ii) linear numerical analysis using a spectral method; and (iii) nonlinear direct numerical simulation using a finite-element method. A satisfactory agreement among the three different sets of solutions is achieved when E <= 10(-4). It is shown that the flow amplitude vertical bar u vertical bar is nearly independent of both the Ekman number E and the libration frequency <(omega)over cap>, always obeying the asymptotic scaling vertical bar u vertical bar = O(epsilon) even though various spherical inertial modes are excited by longitudinal libration at different libration frequencies (omega) over cap. Consequently, resonances do not occur in this system even when (omega) over cap is at the characteristic value of an inertial mode. It is also shown that the pressure difference along the axis of rotation is anomalous: this quantity reaches a sharp peak when (omega) over cap approaches a characteristic value. In contrast, the pressure difference measured at other places in the sphere, such as in the equatorial plane, and the volume-integrated kinetic energy are nearly independent of both the Ekman number E and the libration frequency (omega) over cap. Absence of resonances in a fluid-filled sphere forced by longitudinal libration is explained through the special properties of the analytical solution that satisfies the no-slip boundary condition and is valid for E << 1 and epsilon << 1. |
| WOS标题词 | Science & Technology ; Technology ; Physical Sciences |
| 类目[WOS] | Mechanics ; Physics, Fluids & Plasmas |
| 研究领域[WOS] | Mechanics ; Physics |
| 关键词[WOS] | ZONAL FLOWS ; INERTIAL OSCILLATIONS ; PRECESSING CYLINDER ; SPHEROIDAL CAVITY ; DRIVEN ; MOTION ; WAVES |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000315456800009 |
| 公开日期 | 2014-09-22 |
| 源URL | [http://119.78.226.72//handle/331011/15215]  |
| 专题 | 上海天文台_空间导航与定位技术重点实验室 |
| 作者单位 | 1.Univ Exeter, Dept Math Sci, Exeter EX4 4QF, Devon, England 2.Univ Hong Kong, Dept Math, Pokfulam, Hong Kong, Peoples R China 3.Chinese Acad Sci, Shanghai Astron Observ, Shanghai 200030, Peoples R China 4.Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA |
| 推荐引用方式 GB/T 7714 | Zhang, Keke,Chan, Kit H.,Liao, Xinhao,et al. The non-resonant response of fluid in a rapidly rotating sphere undergoing longitudinal libration[J]. JOURNAL OF FLUID MECHANICS,2013,720:212-235. |
| APA | Zhang, Keke,Chan, Kit H.,Liao, Xinhao,&Aurnou, Jonathan M..(2013).The non-resonant response of fluid in a rapidly rotating sphere undergoing longitudinal libration.JOURNAL OF FLUID MECHANICS,720,212-235. |
| MLA | Zhang, Keke,et al."The non-resonant response of fluid in a rapidly rotating sphere undergoing longitudinal libration".JOURNAL OF FLUID MECHANICS 720(2013):212-235. |
入库方式： OAI收割
来源：上海天文台
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