A Thermodynamic View of Dusty Protoplanetary Disks
A Thermodynamic View of Dusty Protoplanetary Disks
复制标题
尘埃原行星盘的热力学视图
DOI：
--
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
A. Youdin
中科院分区：
文献类型：
--
作者：
M. Lin;A. Youdin
嵌入在气态原行星盘中的小固体受到强烈的尘埃-气体摩擦的影响。因此，紧密结合的尘埃颗粒几乎跟随着气流。这种沿流线的尘气比近似守恒，类似于弱加热和弱冷却的(无尘)气体流动的近似守恒。我们把这个热力学类比发展成一个框架来研究原行星盘中的尘埃气体动力学。我们证明了等温尘埃气体的行为类似于绝热纯气体，有限的尘埃-气体耦合可视为有效的加热/冷却。我们利用这一对应关系推导出：(1)完全耦合的薄尘埃层不会导致轴对称不稳定；(2)如果尘埃在垂直方向上混合得很好，则径向尘埃边缘是不稳定的；(3)流动不稳定必然涉及滞后于尘埃密度的气体压力响应；以及(4)尘埃负载引入了浮力，通常稳定与全球径向温度梯度相关的垂直剪切不稳定。我们还讨论了尘埃与其他流体动力学过程(例如Rossby波不稳定、对流超稳定性和僵尸涡旋)的相似之处，以及如何对现有的纯气体动力学程序进行微小调整来模拟尘埃原始行星盘。
Small solids embedded in gaseous protoplanetary disks are subject to strong dust–gas friction. Consequently, tightly coupled dust particles almost follow the gas flow. This near conservation of the dust-to-gas ratio along streamlines is analogous to the near conservation of entropy along flows of (dust-free) gas with weak heating and cooling. We develop this thermodynamic analogy into a framework to study dusty gas dynamics in protoplanetary disks. We show that an isothermal dusty gas behaves like an adiabatic pure gas, and that finite dust–gas coupling may be regarded as effective heating/cooling. We exploit this correspondence to deduce that (1) perfectly coupled, thin dust layers cannot cause axisymmetric instabilities; (2) radial dust edges are unstable if the dust is vertically well-mixed; (3) the streaming instability necessarily involves a gas pressure response that lags behind dust density; and (4) dust-loading introduces buoyancy forces that generally stabilize the vertical shear instability associated with global radial temperature gradients. We also discuss dusty analogs of other hydrodynamic processes (e.g., Rossby wave instability, convective overstability, and zombie vortices) and how to simulate dusty protoplanetary disks with minor tweaks to existing codes for pure gas dynamics.
吸积盘垂直剪切不稳定性的线性和非线性演化
影响因子：
4.8
作者：
Nelson R
通讯作者：
Nelson R
通过气体和沉积颗粒之间的双向阻力实现固体的自发浓缩
DOI：
10.1051/0004-6361/201526272
发表时间：
2016
期刊：
arXiv: Earth and Planetary Astrophysics
影响因子：
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作者：
Lambrechts;Johansen;Capelo;Bodenschatz
通讯作者：
Bodenschatz