Turbulent stresses as a function of shear rate in a local disk model

Abstract

We present local numerical models of accretion disk turbulence driven by the magnetorotational instability with varying shear rate. The resulting turbulent stresses are compared with predictions of a closure model in which triple correlations are modelled in terms of quadratic correlations. This local model uses five nondimensional parameters to describe the properties of the flow. We attempt to determine these closure parameters for our simulations and find that the model does produce qualitatively correct behaviour. In addition, we present results concerning the shear rate dependency of the magnetic to kinetic energy ratio. We find both the turbulent stress ratio and the total stress to be strongly dependent on the shear rate.

8 pages, 5 figures, accepted for publication in Astronomische Nachrichten

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Cited by in corpus (11)

• Characterizing the mean-field dynamo in turbulent accretion disks
• Magnetorotational instability driven dynamos at low magnetic Prandtl numbers
• Local Simulations of the Magneto-rotational Instability in Core-Collapse Supernovae
• Wind-driven Accretion in Transitional Protostellar Disks
• A mean-field approach to the propagation of field patterns in stratified magneto rotational turbulence
• Calibrating passive scalar transport in shear-flow turbulence
• Zero net flux MRI-turbulence in disks $-$ sustenance scheme and magnetic Prandtl number dependence
• Sensitivity of the Magnetorotational Instability to the shear parameter in stratified simulations
• A heuristic model for MRI turbulent stresses in Hall MHD
• Unified treatment of mean-field dynamo and angular-momentum transport in magnetorotational instability-driven turbulence
• Mean-field closure parameters for passive scalar turbulence