The fundamental difference between shear alpha viscosity and turbulent magnetorotational stresses
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The fundamental difference between shear alpha viscosity and turbulent magnetorotational stresses. / Pessah, Martin Elias; Chan, Chi-kwan; Psaltis, Dimitrios.
In: Monthly Notices of the Royal Astronomical Society, Vol. 383, No. 2, 06.12.2006, p. 683-690.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - The fundamental difference between shear alpha viscosity and turbulent magnetorotational stresses
AU - Pessah, Martin Elias
AU - Chan, Chi-kwan
AU - Psaltis, Dimitrios
PY - 2006/12/6
Y1 - 2006/12/6
N2 - Numerical simulations of turbulent, magnetized, differentially rotating flows driven by the magnetorotational instability are often used to calculate the effective values of alpha viscosity that is invoked in analytical models of accretion discs. In this paper we use various dynamical models of turbulent magnetohydrodynamic stresses, as well as numerical simulations of shearing boxes, to show that angular momentum transport in MRI-driven accretion discs cannot be described by the standard model for shear viscosity. In particular, we demonstrate that turbulent magnetorotational stresses are not linearly proportional to the local shear and vanish identically for angular velocity profiles that increase outwards.
AB - Numerical simulations of turbulent, magnetized, differentially rotating flows driven by the magnetorotational instability are often used to calculate the effective values of alpha viscosity that is invoked in analytical models of accretion discs. In this paper we use various dynamical models of turbulent magnetohydrodynamic stresses, as well as numerical simulations of shearing boxes, to show that angular momentum transport in MRI-driven accretion discs cannot be described by the standard model for shear viscosity. In particular, we demonstrate that turbulent magnetorotational stresses are not linearly proportional to the local shear and vanish identically for angular velocity profiles that increase outwards.
KW - astro-ph
U2 - 10.1111/j.1365-2966.2007.12574.x
DO - 10.1111/j.1365-2966.2007.12574.x
M3 - Journal article
VL - 383
SP - 683
EP - 690
JO - Royal Astronomical Society. Monthly Notices
JF - Royal Astronomical Society. Monthly Notices
SN - 0035-8711
IS - 2
ER -
ID: 34382735