We perform direct numerical simulations of rotating Rayleigh-Bénard convection (RRBC) of fluids with low ($\mathrm{Pr}=0.1$) and high ($\mathrm{Pr}\approx 5$) Prandtl numbers in a horizontally periodic layer with no-slip bottom and top boundaries. No-slip boundaries are known to actively promote the formation of plumelike vertical disturbances, through so-called Ekman pumping, that control the ambient flow at sufficiently high rotation rates. At both Prandtl numbers, we demonstrate the presence of competing large-scale vortices (LSVs) in the bulk. Strong buoyant forcing and rotation foster the quasi-two-dimensional turbulent state of the flow that leads to the upscale transfer of kinetic energy that forms the domain-filling LSV condensate. The Ekman plumes from the boundary layers are sheared apart by the large-scale flow, yet we find that their energy feeds the upscale transfer. Our results of RRBC simulations substantiate the emergence of large-scale flows in nature regardless of the specific details of the boundary conditions.

中文翻译：

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快速旋转热对流中埃克曼羽和涡旋冷凝水之间的竞争

我们对低（）流体的旋转Rayleigh-Bénard对流（RRBC）进行直接数值模拟$镨=0.1$）和高（$镨\approx 5$）水平周期层中的Prandtl数，底部和顶部均无滑动。众所周知，防滑边界通过所谓的埃克曼泵浦主动促进羽状垂直扰动的形成，该扰动以足够高的旋转速率控制环境流量。在两个Prandtl数字上，我们都证明了存在大量竞争性大型涡流（LSV）。强力的浮力推动和旋转促进了流体的准二维湍流状态，从而导致动能的高档转移，从而形成了充满磁畴的LSV冷凝物。边界层的埃克曼羽流被大规模的流动剪断，但我们发现它们的能量为高层转移提供了动力。