skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Global Hall-MHD simulations of magnetorotational instability in a plasma Couette flow experiment

Abstract

Global MHD and Hall-MHD numerical simulations relevant to the Madison plasma Couette flow experiment (MPCX) have been performed using the extended MHD code NIMROD. The MPCX has been constructed to study the magnetorotational instability (MRI) in a plasma. The two-fluid Hall effect, which is relevant to some astrophysical situations such as protostellar disks, is also expected to be important in the MPCX. Here, we first derive the local Hall dispersion relation including viscosity, extending earlier work by Balbus and Terquem [Astrophys. J. 552, 235 (2001)]. The predictions of the local analysis are then compared with nonlocal calculations of linear stability of the MRI for a parameter range relevant to the MPCX. It is found that the MHD stability limit and mode structure are altered by the Hall term, and nonlocal analysis is necessary to obtain quantitatively reliable predictions for MPCX. Two-fluid physics also significantly changes the nonlinear evolution and saturation of the axisymmetric MRI. Both the Reynolds and Maxwell stresses contribute significantly to momentum transport. In the Hall regime, when the magnetic field is parallel to the rotation axis, the Maxwell stress is larger than the Reynolds stress (similar to the MHD regime). However, when the magnetic field is antiparallelmore » to the rotation axis in the Hall regime, the Reynolds stress is much larger than the Maxwell stress. To further study the role of non-axisymmetric modes, we have also carried out fully nonlinear MHD computations. Non-axisymmetric modes play an increasingly important role as the magnetic Reynolds number increases and grow to large amplitudes in a saturated turbulent state.« less

Authors:
; ;  [1];  [2]
  1. Center for Magnetic Self-Organization in Laboratory and Astrophysical Plasmas, University of New Hampshire, 8 College Road, Durham, New Hampshire 03824 (United States)
  2. University of Wisconsin, 1150 University Avenue, Madison, Wisconsin 53706 (United States)
Publication Date:
OSTI Identifier:
21546966
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 18; Journal Issue: 6; Other Information: DOI: 10.1063/1.3598481; (c) 2011 American Institute of Physics; Journal ID: ISSN 1070-664X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; AXIAL SYMMETRY; COMPUTERIZED SIMULATION; COUETTE FLOW; DISPERSION RELATIONS; HALL EFFECT; MAGNETIC REYNOLDS NUMBER; MAGNETOHYDRODYNAMICS; PLASMA INSTABILITY; PLASMA SIMULATION; TURBULENCE; VISCOSITY; DIMENSIONLESS NUMBERS; FLUID FLOW; FLUID MECHANICS; HYDRODYNAMICS; INSTABILITY; MECHANICS; REYNOLDS NUMBER; SIMULATION; SYMMETRY; VISCOUS FLOW

Citation Formats

Ebrahimi, F, Lefebvre, B, Bhattacharjee, A, and Forest, C B. Global Hall-MHD simulations of magnetorotational instability in a plasma Couette flow experiment. United States: N. p., 2011. Web. doi:10.1063/1.3598481.
Ebrahimi, F, Lefebvre, B, Bhattacharjee, A, & Forest, C B. Global Hall-MHD simulations of magnetorotational instability in a plasma Couette flow experiment. United States. https://doi.org/10.1063/1.3598481
Ebrahimi, F, Lefebvre, B, Bhattacharjee, A, and Forest, C B. 2011. "Global Hall-MHD simulations of magnetorotational instability in a plasma Couette flow experiment". United States. https://doi.org/10.1063/1.3598481.
@article{osti_21546966,
title = {Global Hall-MHD simulations of magnetorotational instability in a plasma Couette flow experiment},
author = {Ebrahimi, F and Lefebvre, B and Bhattacharjee, A and Forest, C B},
abstractNote = {Global MHD and Hall-MHD numerical simulations relevant to the Madison plasma Couette flow experiment (MPCX) have been performed using the extended MHD code NIMROD. The MPCX has been constructed to study the magnetorotational instability (MRI) in a plasma. The two-fluid Hall effect, which is relevant to some astrophysical situations such as protostellar disks, is also expected to be important in the MPCX. Here, we first derive the local Hall dispersion relation including viscosity, extending earlier work by Balbus and Terquem [Astrophys. J. 552, 235 (2001)]. The predictions of the local analysis are then compared with nonlocal calculations of linear stability of the MRI for a parameter range relevant to the MPCX. It is found that the MHD stability limit and mode structure are altered by the Hall term, and nonlocal analysis is necessary to obtain quantitatively reliable predictions for MPCX. Two-fluid physics also significantly changes the nonlinear evolution and saturation of the axisymmetric MRI. Both the Reynolds and Maxwell stresses contribute significantly to momentum transport. In the Hall regime, when the magnetic field is parallel to the rotation axis, the Maxwell stress is larger than the Reynolds stress (similar to the MHD regime). However, when the magnetic field is antiparallel to the rotation axis in the Hall regime, the Reynolds stress is much larger than the Maxwell stress. To further study the role of non-axisymmetric modes, we have also carried out fully nonlinear MHD computations. Non-axisymmetric modes play an increasingly important role as the magnetic Reynolds number increases and grow to large amplitudes in a saturated turbulent state.},
doi = {10.1063/1.3598481},
url = {https://www.osti.gov/biblio/21546966}, journal = {Physics of Plasmas},
issn = {1070-664X},
number = 6,
volume = 18,
place = {United States},
year = {2011},
month = {6}
}