Computational implementation of a coupled plasma-neutral fluid model

Journal Article · Tue Dec 01 00:00:00 EST 1992 · Journal of Computational Physics; (United States)

DOI:https://doi.org/10.1016/0021-9991(92)90403-L· OSTI ID:6880303

Vold, E L; Najmabadi, F; Conn, R W ^[1]

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1. Univ. of California, Los Angeles (United States)

This paper describes the computational transport of coupled plasma-neutral fluids in the edge region of a toroidally symmetric magnetic confinement device, with applications to the tokamak. The model couples neutral density in a diffusion approximation with a set of transport equations for the plasma including density, classical plasma parallel velocity, anomalous cross-field velocity, and ion and electron temperature equations. The plasma potential, gradient electric fields, drift velocity, and net poloidal velocity are computed as dependent quantities under the assumption of ambipolarity. The implementation is flexible to permit extension in the future to a fully coupled set of nonambipolar momentum equations. The computational method incorporates sonic flow and particle recycling of ions and neutrals at the vessel boundary. A numerically generated orthogonal grid conforms to the poloidal magnetic flux surfaces. Power law differencing based on the SIMPLE relaxation method is modified to accommodate the compressible reactive plasma flow with a semi-implicit diffusion method. Residual corrections are applied to obtain a valid convergence to the steady state solution. Results are presented for a representative divertor tokamak in a high recycling regime, showing strongly peaked neutral and plasma densities near the divertor target. Solutions show large poloidal and radial gradients in the plasma density, potential, and temperatures. These findings may help to understand the strong turbulence experimentally observed in the plasma edge region of the tokamak. 54 refs., 11 figs.

• OSTI ID: 6880303
• Journal Information: Journal of Computational Physics; (United States), Vol. 103:2; ISSN 0021-9991
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
PLASMA SCRAPE-OFF LAYER
TWO-DIMENSIONAL CALCULATIONS
TOKAMAK TYPE REACTORS
COMPUTERIZED SIMULATION
E CODES
EDGE LOCALIZED MODES
MAGNETIC FLUX
MESH GENERATION
PLASMA CONFINEMENT
PLASMA DIAGNOSTICS
BOUNDARY LAYERS
COMPUTER CODES
CONFINEMENT
INSTABILITY
LAYERS
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
SIMULATION
THERMONUCLEAR REACTORS
700310* - Plasma Confinement- (1992-)
990200 - Mathematics & Computers
700330 - Plasma Kinetics
Transport
& Impurities- (1992-)