论文标题
旋转恒星内饰中Tayler不稳定性的磁性水力动力学模拟
Magnetohydrodynamic Simulations of the Tayler Instability in Rotating Stellar Interiors
论文作者
论文摘要
泰勒的不稳定性是一种重要但研究良好的磁流失动力学不稳定性，可能在恒星内部发挥作用。泰勒不稳定性的非线性饱和度知之甚少，并且对恒星辐射区域中的发电机作用和角动量转运产生了至关重要的后果。我们在圆柱形几何形状中对泰勒不稳定性进行三维MHD模拟，包括强浮力和科里奥利力，适合其在逼真的旋转恒星中的运行。不稳定性的线性生长的特征是主要$ m = 1 $振荡，分析期望后的增长率约为增长率。不稳定性的非线性饱和似乎是由继发性剪切不稳定性引起的，还伴随着流动的形态变化。但是，我们认为，非线性饱和可能是通过真实恒星中的其他机制发生的，在现实恒星中，尺度的分离大于我们的模拟所达到的量表。我们还通过扩增轴对称性球磁场来观察发电机的作用，这表明泰勒的不稳定性对于不断发展的恒星的辐射区域中的磁场产生和角动量转运可能很重要。
The Tayler instability is an important but poorly studied magnetohydrodynamic instability that likely operates in stellar interiors. The nonlinear saturation of the Tayler instability is poorly understood and has crucial consequences for dynamo action and angular momentum transport in radiative regions of stars. We perform three-dimensional MHD simulations of the Tayler instability in a cylindrical geometry, including strong buoyancy and Coriolis forces as appropriate for its operation in realistic rotating stars. The linear growth of the instability is characterized by a predominantly $m=1$ oscillation with growth rates roughly following analytical expectations. The non-linear saturation of the instability appears to be caused by secondary shear instabilities and is also accompanied by a morphological change of the flow. We argue, however, that non-linear saturation likely occurs via other mechanisms in real stars where the separation of scales is larger than those reached by our simulations. We also observe dynamo action via the amplification of the axisymmetric poloidal magnetic field, suggesting that Tayler instability could be important for magnetic field generation and angular momentum transport in the radiative regions of evolving stars.
