Particle dynamics in discs with turbulence generated by the vertical shear instability
Particle dynamics in discs with turbulence generated by the vertical shear instability
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具有由垂直剪切不稳定产生的湍流的圆盘中的颗粒动力学
DOI：
10.1051/0004-6361/201527716
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
M.H.R.
中科院分区：
文献类型：
--
作者：
M.H.R.
在低内禀电离情况下，在吸积盘中产生湍流的候选者中，垂直剪切不稳定性（VSI）已成为一个有趣的候选者，因为它完全依赖于角速度的垂直梯度。现有的数值模拟表明，α值的几倍10- 4aimsThe颗粒的增长在行星形成阶段的早期是由嵌入的尘埃颗粒的动力学。在这里，我们解决，特别是，在集中粒子产生overdensities和低碰撞velocity.MethodsWe执行三维（3D）数值流体动力学模拟的吸积盘周围的年轻恒星，包括辐射传输和辐射从中央星星的效率。嵌入的颗粒的运动的尺寸范围内的一个分数的mm到几个m的使用标准的阻力formulation.ResultsWe确认，在现实条件下，VSI是能够产生湍流在全三维原行星盘。辐照后的圆盘显示出10 ~ 60 Au范围内的湍流。气体的平均径向运动是这样的，即它在中平面附近向内定向，而在表面层中向外定向。我们发现，大颗粒的漂移与预期的速度向内，而小颗粒可以经历向外漂移的阶段。此外，颗粒表现出聚束行为与overdensities达到5倍的平均值，这是最强的无量纲停止时间周围unity.ConclusionsParticles在一个VSI湍流盘集中在大规模的湍流漩涡，并显示低的相对速度，允许增长的碰撞。所达到的过密度也将使流动不稳定性的开始，进一步增强颗粒生长。在更高的圆盘高度处，小颗粒的向外漂移使得太阳系中经过处理的高温材料能够传输到更远的距离。
ContextAmong the candidates for generating turbulence in accretion discs in situations with low intrinsic ionization, the vertical shear instability (VSI) has become an interesting candidate, since it relies purely on a vertical gradient in the angular velocity. Existing numerical simulations have shown thatα-values a few times 10-4can be generated.AimsThe particle growth in the early planet formation phase is determined by the dynamics of embedded dust particles. Here, we address, in particular, the efficiency of VSI-turbulence in concentrating particles to generate overdensities and low collision velocities.MethodsWe perform three-dimensional (3D) numerical hydrodynamical simulations of accretion discs around young stars that include radiative transport and irradiation from the central star. The motion of embedded particles within a size range of a fraction of mm up to several m is followed using standard drag formula.ResultsWe confirm that, under realistic conditions, the VSI is able to generate turbulence in full 3D protoplanetary discs. The irradiated disc shows turbulence within 10 to 60 au. The mean radial motion of the gas is such that it is directed inward near the midplane and outward in the surface layers. We find that large particles drift inward with the expected speed, while small particles can experience phases of outward drift. Additionally, the particles show bunching behaviour with overdensities reaching five times the average value, which is strongest for dimensionless stopping times around unity.ConclusionsParticles in a VSI-turbulent discs are concentrated in large-scale turbulent eddies and show low relative speeds that allow for growing collisions. The reached overdensities will also enable the onset of streaming instabilities, further enhancing particle growth. The outward drift for small particles at higher disk elevations enable the transport of processed high temperature material in the solar system to greater distances.
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DOI：
10.1086/344743
发表时间：
2002-11
期刊：
The Astrophysical Journal
影响因子：
--
作者：
H. Klahr;Peter Bodenheimer UCOLick Observatory;C. Physics;I. F. A. U. Astrophysik;U. Tuebingen;H Germany
通讯作者：
H. Klahr;Peter Bodenheimer UCOLick Observatory;C. Physics;I. F. A. U. Astrophysik;U. Tuebingen;H Germany
DOI：
--
发表时间：
1987
期刊：
影响因子：
--
作者：
D. Lin;J. Pringle
通讯作者：
J. Pringle
影响因子：
3.2
作者：
Y. Nakagawa;M. Sekiya;C. Hayashi
通讯作者：
Y. Nakagawa;M. Sekiya;C. Hayashi
从霍奇到特维斯特
DOI：
--
发表时间：
2010
期刊：
影响因子：
--
作者：
Teruhiko Matsubara;Kazutoshi Iijimaa;Takayoshi Watanabe;Takahiro Hohsaka;Toshinori Sato;田淵俊人;望月拓郎
通讯作者：
望月拓郎
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