Investigation of the dependence of angular momentum transport on spatial scales for construction of differential rotation
Investigation of the dependence of angular momentum transport on spatial scales for construction of differential rotation
复制标题
研究角动量传输对空间尺度的依赖性，以构建微分旋转
DOI：
10.1093/mnras/stac3804
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发表时间：
2022
影响因子：
4.8
通讯作者：
Hotta H
中科院分区：
文献类型：
--
作者：
Mori K;Hotta H
通过对类太阳恒星的数值模拟，研究了角动量输运(AMT)对空间尺度的依赖关系。人们认为湍流在太阳差异旋转(DR)的形成中起着至关重要的作用。在一种广泛使用的分析DR形成机制的方法中，流动被分为两个分量，平均流和湍流，其中，湍流包括广泛的空间尺度。预计AMT的特点将取决于规模。在本研究中，我们通过分解角动量通量来研究角动量通量在空间尺度上的依赖关系。我们与反太阳(快极)和太阳型(快赤道)Dr的结果进行了比较，我们的结论是：(1)在旋转约束系统中，径向向外的AMT是大范围的(60 mm≤L和lt；120 mm)。(2)即使在尺度积分AMF为负的情况下，我们有时也会在某些尺度上观察到正的AMF。(3)小尺度湍流倾向于将角动量径向向内输送，导致反太阳DR，说明高分辨率的模拟是类太阳DR的一个负面因素。我们对AMF的分解方法有助于深入了解DR的角动量和构造机制。
We investigate the dependence of the angular momentum transport (AMT) on the spatial scales with numerical simulation of solar-like stars. It is thought that turbulence has an essential role in constructing solar differential rotation (DR). In a widely used method to analyse the construction mechanism of DR, the flow is divided into two components, ‘mean flow’ and ‘turbulence’, where ‘turbulence’ includes a broad spectrum of spatial scales. The features of the AMT are expected to depend on the scale. In this study, we decompose the angular momentum flux (AMF) to investigate the dependence of the AMF on the spatial scale. We compare the results with anti-solar (fast pole) and solar-type (fast equator) DR. Our conclusions are summarized as (1) Radially outward AMT is seen on a large scale (60 Mm ≤L< 120 Mm) in rotationally constrained systems. (2) Even when the scale-integrated AMF is negative, we sometimes observe positive AMF on certain scales. (3) Small-scale turbulence tends to transport the angular momentum radially inward and causes the anti-solar DR, indicating that high-resolution simulation is a negative factor for solar-like DR. Our method to decompose the AMF provides a deep understanding of the angular momentum and construction mechanism of DR.