Large-scale vortices and zonal flows in spherical rotating convection
Large-scale vortices and zonal flows in spherical rotating convection
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球形旋转对流中的大尺度涡流和纬向流
DOI：
10.1017/jfm.2020.1151
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发表时间：
2020-12
影响因子：
3.7
通讯作者：
Jackson Andrew
中科院分区：
文献类型：
--
作者：
Lin Yufeng;Jackson Andrew
摘要出于对恒星和行星内部动力学的理解，我们对旋转球中的Boussinesq对流进行了一组直接数值模拟。该域是内部加热与固定的温度和无应力的边界条件，但固定的热流和无滑移的边界条件也被简要考虑。我们特别关注的大尺度相干结构和平均纬向流，可以在系统中发展。在普兰特数为1时，随着热力强迫（由Rayleigh数测量）增加到对流开始的值以上，我们发现一个驰豫振荡区，随后是地转湍流区。除此之外，我们第一次看到在旋转轴上形成的大尺度相干涡旋的存在。所有制度的边界都很好地描述了对流Rossby数$Ro_c$的临界值，从振荡到地转湍流的过渡，然后到大尺度涡制度的值$Ro_c\约0.2$和$Ro_c\约1.5$，分别。纬向流由对流Rossby数控制，并在流从地转湍流区向大尺度涡旋区过渡时改变其方向。虽然非纬向流速和热传递可以用地转湍流区的惯性尺度来描述，但大尺度涡的形成似乎会降低非纬向流速和对流热传递的效率。
Abstract Motivated by understanding the dynamics of stellar and planetary interiors, we have performed a set of direct numerical simulations of Boussinesq convection in a rotating full sphere. The domain is internally heated with fixed temperature and stress-free boundary conditions, but fixed heat flux and no-slip boundary conditions are also briefly considered. We particularly focus on the large-scale coherent structures and the mean zonal flows that can develop in the system. At Prandtl number of unity, as the thermal forcing (measured by the Rayleigh number) is increased above the value for the onset of convection, we find a relaxation oscillation regime, followed by a geostrophic turbulence regime. Beyond this we see for the first time the existence of large-scale coherent vortices that form on the rotation axis. All regime boundaries are well described by critical values of the convective Rossby number $Ro_c$, with transitions from oscillatory to geostrophic turbulence, and then to the large-scale vortex regime at values $Ro_c\approx 0.2$ and $Ro_c\approx 1.5$, respectively. The zonal flow is controlled by the convective Rossby number and changes its direction when the flow transitions from the geostrophic turbulence regime to the large-scale vortex regime. While the non-zonal flow speed and heat transfer can be described by the so-called inertial scaling in the geostrophic turbulence regime, the formation of large-scale vortices appears to reduce both the non-zonal flow speed and the efficiency of convective heat transfer.
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DOI：
10.1016/j.jcp.2015.10.056
发表时间：
2016-01
期刊：
J. Comput. Phys.
影响因子：
--
作者：
P. Marti;A. Jackson
通讯作者：
P. Marti;A. Jackson
影响因子：
1.7
作者：
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通讯作者：
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影响因子：
3.1
作者：
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通讯作者：
Meredith Plumley;K. Julien
影响因子：
5.3
作者：
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通讯作者：
Mayr, Hans G.
影响因子：
8.6
作者：
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通讯作者：
Antonio M. Rubio;K. Julien;E. Knobloch;J. Weiss