论文标题
快速旋转对流的地质湍流方案的实验观察
Experimental observation of the geostrophic turbulence regime of rapidly rotating convection
论文作者
论文摘要
行星和恒星内部的湍流对流与全球旋转之间的竞争决定了热量和示踪剂的运输以及磁场的产生。这些物体在动态状态下运行,从弱旋转对流到快速旋转对流的“地球湍流”制度。然而,尽管在过去的十年中,在全球范围内设计了越来越多的对流电池,但后一种政权在实验室中仍然难以捉摸。基于最新的实验方法,我们报告了与该缩放制度的定量一致性中的热传输测量值,实验缩放范围是针对理想化设置的直接数值模拟(DNS)验证的。实验和DNS的缩放指数与地质湍流预测非常吻合。缩放率的预先因素比以前理想化的数值研究中诊断的缩放率更大,这表明热传输效率对热源和水槽的精确分布的意外敏感性,这从行星到恒星都有很大变化。
The competition between turbulent convection and global rotation in planetary and stellar interiors governs the transport of heat and tracers, as well as magnetic-field generation. These objects operate in dynamical regimes ranging from weakly rotating convection to the `geostrophic turbulence' regime of rapidly rotating convection. However, the latter regime has remained elusive in the laboratory, despite a worldwide effort to design ever-taller rotating convection cells over the last decade. Building on a recent experimental approach where convection is driven radiatively, we report heat transport measurements in quantitative agreement with this scaling regime, the experimental scaling-law being validated against direct numerical simulations (DNS) of the idealized setup. The scaling exponent from both experiments and DNS agrees well with the geostrophic turbulence prediction. The prefactor of the scaling-law is greater than the one diagnosed in previous idealized numerical studies, pointing to an unexpected sensitivity of the heat transport efficiency to the precise distribution of heat sources and sinks, which greatly varies from planets to stars.