论文标题
垂直剪切不稳定性的高分辨率参数研究
High Resolution Parameter Study of the Vertical Shear Instability
论文作者
论文摘要
原星盘的理论模型表明垂直剪切不稳定性（VSI）是解释磁盘死区湍流的主要候选者。但是，对VSI的模拟尚未显示出一致的关键磁盘湍流参数，例如应力与压力比$α$。我们旨在通过对VSI进行参数研究来调和这些不同的值，重点关注磁盘密度梯度$ P $和长宽比$ h：= h/r $。我们将全部2 $π$ 3D模拟用于选定的两个参数集。所有模拟都以1000个参考轨道的形式进化，分辨率为每h 18个单元。我们发现，模拟中的饱和应力与压力比取决于磁盘的纵横比，与传统的$α$模型相比，$α\ propto h^{2.6} $的\ propto {strong}缩放比例，其中粘度缩放为$ν\ propto tapt \ propto f proptotty propto propto propto propto proptoαH^2 $与常数$α$α$α$。我们还观察到在所有研究的参数中始终形成大规模涡旋。涡流显示出$χ\ \ 10 $的均匀纵横比，径向宽度约为1.5 $ h $。通过我们的发现，我们可以调和从等温度和辐射流体动力学模型的应力与压力比报告的不同值，并显示VSI的长期演化效应，这可以帮助地球形成。
Theoretical models of protoplanetary disks have shown the Vertical Shear Instability (VSI) to be a prime candidate to explain turbulence in the dead zone of the disk. However, simulations of the VSI have yet to show consistent levels of key disk turbulence parameters like the stress-to-pressure ratio $α$. We aim to reconcile these different values by performing a parameter study on the VSI with focus on the disk density gradient $p$ and aspect ratio $h := H/R$. We use full 2$π$ 3D simulations of the disk for chosen set of both parameters. All simulations are evolved for 1000 reference orbits, at a resolution of 18 cells per h. We find that the saturated stress-to-pressure ratio in our simulations is dependent on the disk aspect ratio with a \review{strong} scaling of $α\propto h^{2.6}$, in contrast to the traditional $α$ model, where viscosity scales as $ν\propto αh^2$ with a constant $α$. We also observe consistent formation of large scale vortices across all investigated parameters. The vortices show uniformly aspect ratios of $χ\approx 10$ and radial widths of approximately 1.5 $H$. With our findings we can reconcile the different values reported for the stress-to-pressure ratio from both isothermal and radiation hydrodynamics models, and show long-term evolution effects of the VSI that could aide in the formation of planetesimals.
