INDUCED TURBULENCE AND THE DENSITY STRUCTURE OF THE DUST LAYER IN A PROTOPLANETARY DISK
INDUCED TURBULENCE AND THE DENSITY STRUCTURE OF THE DUST LAYER IN A PROTOPLANETARY DISK
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DOI：
10.1088/0004-637x/744/2/101
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发表时间：
2011-09
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影响因子：
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通讯作者：
T. Takeuchi;T. Muto;S. Okuzumi;N. Ishitsu;S. Ida
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作者：
T. Takeuchi;T. Muto;S. Okuzumi;N. Ishitsu;S. Ida
本文从尘埃吸积的能量学出发，研究了原行星盘尘埃层中由于气体阻力引起的湍流。我们估计湍流强度提供的能量由尘埃吸积，使用的径向漂移速度的尘埃粒子在层流盘。我们的湍流强度的估计同意与以前的分析和数值研究的湍流引起的开尔文-亥姆霍兹和/或流不稳定性的粒子与停止时间小于开普勒时间。对于这样的小颗粒，当尘埃与气体的比率为Ceff 1/2 eff（hg/r）<$10 −2时，预计会出现最强的湍流，其中Ceff <$0.2表示湍流的能量供应效率，hg/r <$5 × 10−2是气体盘的纵横比。最大粘性参数为αmax <$CeffTs（hg/r）2 <$10 − 4 Ts，其中Ts（< 1）是尘埃粒子的无量纲停止时间。通过任何方法对标准值10−2的尘气比进行修改，都会导致湍流减弱和粉尘层变薄，从而可能加速粉尘颗粒的生长过程。
We study the turbulence induced in the dust layer of a protoplanetary disk based on the energetics of dust accretion due to gas drag. We estimate turbulence strength from the energy supplied by dust accretion, using the radial drift velocity of the dust particles in a laminar disk. Our estimate of the turbulence strength agrees with previous analytical and numerical research on the turbulence induced by Kelvin–Helmholtz and/or streaming instabilities for particles with stopping time less than the Keplerian time. For such small particles, the strongest turbulence is expected to occur when the dust-to-gas ratio of the disk is ∼C1/2eff(hg/r) ∼ 10−2, where Ceff ≈ 0.2 represents the energy supply efficiency to turbulence and hg/r ∼ 5 × 10−2 is the aspect ratio of the gas disk. The maximum viscosity parameter is αmax ∼ CeffTs(hg/r)2 ∼ 10−4Ts, where Ts(< 1) is the non-dimensional stopping time of the dust particles. Modification to the dust-to-gas ratio from the standard value, 10−2, by any process, results in weaker turbulence and a thinner dust layer, and consequently may accelerate the growth process of the dust particles.