Nonlinear gyrofluid description of turbulent magnetized plasmas

Journal Article · Fri May 01 04:00:00 EDT 1992 · Physics of Fluids B; (United States)

DOI:https://doi.org/10.1063/1.860129· OSTI ID:7297368

Brizard, A ^[1]

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1. Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720 (United States)

Nonlinear {ital gyrofluid} equations are obtained from the {ital gyrocenter}-{ital fluid} moments of the nonlinear gyrokinetic Vlasov equation, which describes an equilibrium magnetized nonuniform plasma perturbed by electromagnetic field fluctuations ({delta}{phi},{delta}{ital A}{sub {parallel}},{delta}{ital B}{sub {parallel}}), whose space-time scales satisfy the gyrokinetic ordering: {omega}{much lt}{Omega}{sub {ital i}}, {vert bar}{ital k}{sub {parallel}}{vert bar}/{ital k}{sub {perpendicular}}{much lt}1, and {epsilon}{sub {perpendicular}}{equivalent to}({ital k}{sub {perpendicular}}{rho}{sub {ital i}}){sup 2}{congruent}O(1). These low-frequency ({ital reduced}) fluid equations contain terms of arbitrary order in {epsilon}{sub {perpendicular}} and take into account the nonuniformity in the equilibrium density and temperature of the ion and electron species, as well as the nonuniformity in the equilibrium magnetic field. From the gyrofluid equations, one can systematically derive nonlinear reduced fluid equations with finite-Larmor-radius (FLR) corrections, which contain linear and nonlinear terms of O({epsilon}{sub {perpendicular}}), by expressing the {ital gyrocenter}-{ital fluid} moments appearing in the gyrofluid equations in terms of the {ital particle}-{ital fluid} moments, and then keeping terms up to O({epsilon}{sub {perpendicular}}) in the {epsilon}{sub {perpendicular}} expansion of the gyrofluid equations. By using gyrocenter-fluid moments, this new gyrofluid approach effectively bypasses the issue of the gyroviscous cancellations, while retaining all the important diamagnetic effects and the gyroviscous corrections. From the present FLR-corrected reduced fluid equations, the reduced Braginskii equations are recoverd for the ion and electron species (without collisional dissipation) and the ideal reduced magnetohydrodynamic (MHD) equations (in the absence of FLR effects).

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 7297368
• Journal Information: Physics of Fluids B; (United States), Journal Name: Physics of Fluids B; (United States) Vol. 4:5; ISSN 0899-8221; ISSN PFBPE
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700330* -- Plasma Kinetics
Transport
& Impurities-- (1992-)
700370 -- Plasma Fluid & MHD Properties-- (1992-)
EQUATIONS
EQUILIBRIUM
FLUCTUATIONS
FLUID FLOW
INSTABILITY
KINETIC EQUATIONS
LARMOR RADIUS
MAGNETIZATION
MHD EQUILIBRIUM
MOMENTS METHOD
PLASMA
PLASMA DRIFT
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
TURBULENT FLOW
VARIATIONS