论文标题
稳定分层的湍流中的小规模发电机
Small-Scale Dynamo in Stably Stratified Turbulence
论文作者
论文摘要
我们介绍了稳定分层湍流中小规模发电机的三个主要特性的数值研究：运动标准，生长速率和磁场各向异性的性质。结果表明，所有三个发电机性能都由Ozmidov量表与粘性或电阻尺度之间的尺度分离控制。除了临界磁性雷诺数外，这还允许定义临界浮力和磁性浮力雷诺数，分别在高和低磁性prandtl数字方面分层小型发电。恒星辐射区中的小规模发电机的存在可能会通过导致差异旋转区域中的麦克斯韦应力和/或影响大规模发电机机制来影响动力学。以太阳辐射区为代表性的示例并应用了发作标准，我们发现分层足够强，可以使小规模的发电机在太阳能lo速的稳定分层的湍流中略微活跃。
We present numerical investigations into three principal properties of the small-scale dynamo in stably stratified turbulence: the onset criterion, the growth rate, and the nature of the magnetic field anisotropy in the kinematic regime. The results suggest that all three dynamo properties are controlled by the scale separation between the Ozmidov scale and the viscous or resistive scale. In addition to the critical magnetic Reynolds number, this allows for the definition of critical buoyancy and magnetic buoyancy Reynolds numbers for stratified small-scale dynamo onset in the high and low magnetic Prandtl number regimes, respectively. The presence of a small-scale dynamo in stellar radiative zones could affect dynamics through resulting Maxwell stresses and/or influence large-scale dynamo mechanisms in regions of differential rotation. Taking the solar radiative zone as a representative example and applying the onset criterion, we find that the stratification is strong enough to make the small-scale dynamo marginally active in the stably stratified turbulence of the solar tachocline.
