Dust Transport in Protoplanetary Disks with Wind-driven Accretion. (arXiv:2102.01110v2 [astro-ph.EP] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Hu_Z/0/1/0/all/0/1">Zitao Hu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bai_X/0/1/0/all/0/1">Xue-Ning Bai</a>
It has recently been shown that the inner region of protoplanetary disks
(PPDs) is governed by wind-driven accretion, and the resulting accretion flow
showing complex vertical profiles. Such complex flow structures are further
enhanced due to the Hall effect, especially when the background magnetic field
is aligned with disk rotation. We investigate how such flow structures impact
global dust transport via Monte-Carlo simulations, focusing on two scenarios.
In the first scenario, the toroidal magnetic field is maximized in the miplane,
leading to accretion and decretion flows above and below. In the second
scenario, the toroidal field changes sign across the midplane, leading to an
accretion flow at the disk midplane, with decretion flows above and below. We
find that in both cases, the contribution from additional gas flows can still
be accurately incorporated into the advection-diffusion framework for
vertically-integrated dust transport, with enhanced dust radial diffusion up to
an effective $alpha^{rm eff}sim10^{-2}$ for strongly coupled dust, even when
background turbulence is weak $alpha<10^{-4}$. Dust radial drift is also
modestly enhanced in the second scenario. We provide a general analytical
theory that accurately reproduces our simulation results, thus establishing a
framework to model global dust transport that realistically incorporates
vertical gas flow structures. We also note that the theory is equally
applicable to the transport of chemical species.
It has recently been shown that the inner region of protoplanetary disks
(PPDs) is governed by wind-driven accretion, and the resulting accretion flow
showing complex vertical profiles. Such complex flow structures are further
enhanced due to the Hall effect, especially when the background magnetic field
is aligned with disk rotation. We investigate how such flow structures impact
global dust transport via Monte-Carlo simulations, focusing on two scenarios.
In the first scenario, the toroidal magnetic field is maximized in the miplane,
leading to accretion and decretion flows above and below. In the second
scenario, the toroidal field changes sign across the midplane, leading to an
accretion flow at the disk midplane, with decretion flows above and below. We
find that in both cases, the contribution from additional gas flows can still
be accurately incorporated into the advection-diffusion framework for
vertically-integrated dust transport, with enhanced dust radial diffusion up to
an effective $alpha^{rm eff}sim10^{-2}$ for strongly coupled dust, even when
background turbulence is weak $alpha<10^{-4}$. Dust radial drift is also
modestly enhanced in the second scenario. We provide a general analytical
theory that accurately reproduces our simulation results, thus establishing a
framework to model global dust transport that realistically incorporates
vertical gas flow structures. We also note that the theory is equally
applicable to the transport of chemical species.
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