Heat Transport in the Geostrophic Regime of Rotating Rayleigh-Benard Convection
Heat Transport in the Geostrophic Regime of Rotating Rayleigh-Benard Convection
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DOI：
10.1103/physrevlett.113.114301
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发表时间：
2014-09-08
影响因子：
8.6
通讯作者：
Niemela, Joseph J.
中科院分区：
文献类型：
--
作者：
Ecke, Robert E.;Niemela, Joseph J.
我们报告的实验测量旋转Rayleigh-Benard对流在一个圆柱形对流单体的纵横比γ = 1-2的热传输。该流体是具有普朗特数Pr = 0.7的氦气。瑞利数的控制参数范围为4 x 10（9）< Ra < 4 x 10（11），埃克曼数为2 x 10（-7）< Ek < 3 x 10（-5）（对应于泰勒数4 x 10（9）< Ta < 1 x 10（14）和对流Rossby数0.07 < Ro < 5）。通过对热传输Nu的实验测量，我们确定了弱旋转湍流对流向旋转主导的地转对流的转变。热输运，最好使用参数RaEk（β），1.65 <β < 1.8，定义了两个边界的Ra/Ra-c与Ek的相图和阐明的地转湍流制度的旋转热对流的属性。我们发现Nu类似于（Ra/Ra-c）（gamma），其中gamma从直接测量近似为1，并且从标度参数推断出1.2 < gamma < 1.6。
We report experimental measurements of heat transport in rotating Rayleigh-Benard convection in a cylindrical convection cell with an aspect ratio of Gamma = 1-2. The fluid is helium gas with a Prandtl number Pr = 0.7. The range of control parameters for Rayleigh numbers 4 x 10(9) < Ra < 4 x 10(11) and for Ekman numbers 2 x 10(-7) < Ek < 3 x 10(-5) (corresponding to Taylor numbers 4 x 10(9) < Ta < 1 x 10(14) and convective Rossby numbers 0.07 < Ro < 5). We determine the transition from weakly rotating turbulent convection to rotation dominated geostrophic convection through experimental measurements of the heat transport Nu. The heat transport, best collapsed using a parameter RaEk(beta) with 1.65 < beta < 1.8, defines two boundaries in the phase diagram of Ra/Ra-c versus Ek and elucidates properties of the geostrophic turbulence regime of rotating thermal convection. We find Nu similar to (Ra/Ra-c)(gamma) with gamma approximate to 1 from direct measurement and 1.2 < gamma < 1.6 inferred from scaling arguments.