Rotating convection with centrifugal buoyancy: Numerical predictions for laboratory experiments
Rotating convection with centrifugal buoyancy: Numerical predictions for laboratory experiments
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DOI：
10.1103/physrevfluids.4.073501
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发表时间：
2019-07-19
影响因子：
2.7
通讯作者：
Aurnou, Jonathan M.
中科院分区：
文献类型：
--
作者：
Horn, Susanne;Aurnou, Jonathan M.
在科里奥利-离心对流（C-3）中，浮力效应不仅由于重力加速度在垂直方向上驱动对流运动，而且由于离心加速度在径向方向上驱动对流运动[Horn and Aurnou， Phys]。Rev . Lett. 120,204502(2018)]。在这里，我们利用数值模拟的灵活性来独立改变引力罗斯比数Ro（平行于）和旋转弗劳德数Fr，从而在最广泛的可用参数空间上研究C-3。根据我们的模拟结果，我们给出了旋转对流的实验室实验的预测，其中不可避免地包括离心效应。我们特别关注温度场的空间分布。与忽略离心浮力的理想科里奥利对流不同，随着弗劳德数的增加，垂直温度分布具有强烈的径向依赖性，并表现出自上而下的不对称性。在准循环状态下，流体体积中心的温度表现出强烈的增强，达到接近底边界温度的值，而侧壁的温度远低于算术平均值。我们进一步发现Hart和Ohlsen的轴对称线性模型[Phys。流体[11,2101(1999)]不能用于准确预测测量的中心温度，并根据我们的全三维模拟结果提供另一种经验函数。给出了实验室实验中局部热测量的最佳位置，以估计离心影响旋转对流情况下的整体换热和垂直平均温度分布。
In Coriolis-centrifugal convection (C-3), buoyancy effects not only drive convective motions in the vertical direction due to the gravitational acceleration but also in the radial direction due to the centrifugal acceleration [Horn and Aurnou, Phys. Rev, Lett. 120, 204502 (2018)]. Here, we use the flexibility of numerical simulations to vary the gravitational Rossby number Ro(parallel to) and the rotational Froude number Fr independently and thereby study C-3 over the broadest available parameter space. Based on our simulation results we give predictions for laboratory experiments of rotating convection, which inevitably include centrifugal effects. We especially focus on the spatial distribution of the temperature field. Unlike idealized Coriolis convection in which centrifugal buoyancy is neglected, the vertical temperature profiles become strongly radially dependent and exhibit a top-bottom asymmetry with increasing Froude number. In the quasicyclostrophic regime the temperature in the center of the fluid volume shows a strong enhancement, reaching values close to the bottom boundary temperature, whereas the temperatures at the sidewall are well below the arithmetic mean. We find further that the axisymmetric, linear model of Hart and Ohlsen [Phys. Fluids 11, 2101 (1999)] cannot be used to accurately predict the measured center temperatures, and provide an alternative empirical function based on our fully three-dimensional simulation results. Suggestions are given for the optimal local thermal measurement positions in laboratory experiments to estimate the global heat transfer and the vertical mean-temperature profiles in centrifugally affected rotating convection cases.