Vertical Structure and Turbulent Saturation Level in Fully Radiative Protoplanetary Disc Models
Vertical Structure and Turbulent Saturation Level in Fully Radiative Protoplanetary Disc Models
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全辐射原行星盘模型中的垂直结构和湍流饱和度
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
R. Kissmann
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文献类型：
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作者：
M. Flaig;W. Kley;R. Kissmann
利用三维辐射磁流体动力学模拟方法研究了一个大质量（~ 10 0 0 0 g cm-2 at 1 Au）原行星盘模型.圆盘的垂直结构由磁旋转湍流引起的湍流加热和辐射冷却之间的平衡自洽地确定。关于垂直结构，可以区分两个不同的区域：一个气体压力占主导地位，光学厚的中平面区域，其中大部分的耗散发生，和一个磁为主，光学薄的日冕，这是占主导地位的强烈冲击。在光球层处，湍流是超音速的（M ~ 2），这与以往年轻天体光谱拟合的结果一致。众所周知，MRI诱导湍流模拟中的湍流饱和度确实取决于数值因素，例如数值分辨率和盒子尺寸。然而，通过在不同的分辨率（使用高达64 × 128 × 512的网格单元）和不同的盒子大小（在垂直方向上具有高达16个压力刻度高度）下执行一套运行，我们发现，一旦在垂直方向上实现了足够的分辨率，饱和度水平和加热速率都显示出明显的收敛趋势。
We investigate a massive (Σ ~ 10 000 g cm -2 at 1 au) protoplanetary disc model by means of 3D radiation magnetohydrodynamic simulations. The vertical structure of the disc is determined self-consistently by a balance between turbulent heating caused by the magnetorotational turbulence and radiative cooling. Concerning the vertical structure, two different regions can be distinguished: a gas-pressure-dominated, optically thick mid-plane region where most of the dissipation takes place, and a magnetically dominated, optically thin corona which is dominated by strong shocks. At the location of the photosphere, the turbulence is supersonic (M ~ 2), which is consistent with previous results obtained from the fitting of spectra of young stellar objects. It is known that the turbulent saturation level in simulations of MRI-induced turbulence does depend on numerical factors such as the numerical resolution and the box size. However, by performing a suite of runs at different resolutions (using up to 64 x 128 x 512 grid cells) and with varying box sizes (with up to 16 pressure scaleheights in the vertical direction), we find that both the saturation levels and the heating rates show a clear trend to converge once a sufficient resolution in the vertical direction has been achieved.