论文标题
观察实验室中轴对称标准磁化不稳定
Observation of axisymmetric standard magnetorotational instability in the laboratory
论文作者
论文摘要
我们报告了第一个直接证据表明，在泰勒 - 孔子中的磁化液 - 金属剪切流中的轴对称标准磁化不稳定性（SMRI）中，具有独立旋转和电动导致端盖的磁化液 - 金属剪切流。当沿旋转轴施加均匀的垂直磁场$ b_i $时，由于残留物ekman循环的磁化，内部气缸上测得的径向磁场$ b_r $随着小磁性雷诺数$ rm $的线性增加。轴对称SMRI的发作是从实验和非线性数值模拟的关键$ $ $ $的非线性增加中确定的。轴对称SMRI仅在足够大的$ $ $ $和中间$ b_i $中存在，这是一致的，符合理论预测。我们的模拟进一步表明，轴对称SMRI会导致速度和磁场在散装区域中造成轴向角动量的外向通量，就像在积聚磁盘中一样。
We report the first direct evidence for the axisymmetric standard magnetorotational instability (SMRI) from a combined experimental and numerical study of a magnetized liquid-metal shear flow in a Taylor-Couette cell with independently rotating and electrically conducting end caps. When a uniform vertical magnetic field $B_i$ is applied along the rotation axis, the measured radial magnetic field $B_r$ on the inner cylinder increases linearly with a small magnetic Reynolds number $Rm$ due to the magnetization of the residue Ekman circulation. Onset of the axisymmetric SMRI is identified from the nonlinear increase of $B_r$ beyond a critical $Rm$ in both experiments and nonlinear numerical simulations. The axisymmetric SMRI exists only at sufficiently large $Rm$ and intermediate $B_i$, a feature consistent with theoretical predictions. Our simulations further show that the axisymmetric SMRI causes the velocity and magnetic fields to contribute an outward flux of axial angular momentum in the bulk region, just as it should in accretion disks.
