On the necessary conditions for bursts of convection within the rapidly rotating cylindrical annulus
On the necessary conditions for bursts of convection within the rapidly rotating cylindrical annulus
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DOI：
10.1063/1.4711398
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发表时间：
2012-06
影响因子：
4.6
通讯作者：
R. Teed;C. Jones;Rainer Hollerbach
中科院分区：
文献类型：
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作者：
R. Teed;C. Jones;Rainer Hollerbach
在旋转对流系统中经常发现纬向流。这些喷流不仅是由对流驱动的，它们还可以对对流的性质产生深远的影响。在这项工作中，圆柱形的环形几何形状被利用，以进行非线性模拟，寻求产生强大的带状流和多个射流。参数制度扩展到普朗特数是不统一的。多个射流被发现是间隔根据莱茵缩放的纬向流速度的基础上，而不是对流速度。在一定条件下，非线性对流以准周期爆发的形式出现。平均场的稳定性分析进行了一个基本状态，包含两个纬向流和平均温度梯度从非线性模拟。对流增长率波动与这两个平均数量表明，这两个都是必要的，以爆裂现象的发生。
Zonal flows are often found in rotating convective systems. Not only are these jet-flows driven by the convection, they can also have a profound effect on the nature of the convection. In this work the cylindrical annulus geometry is exploited in order to perform nonlinear simulations seeking to produce strong zonal flows and multiple jets. The parameter regime is extended to Prandtl numbers that are not unity. Multiple jets are found to be spaced according to a Rhines scaling based on the zonal flow speed, not the convective velocity speed. Under certain conditions the nonlinear convection appears in quasi-periodic bursts. A mean field stability analysis is performed around a basic state containing both the zonal flow and the mean temperature gradient found from the nonlinear simulations. The convective growth rates are found to fluctuate with both of these mean quantities suggesting that both are necessary in order for the bursting phenomenon to occur.