Fluid/kinetic hybrid moment description of plasmas via a Chapman-Enskog-like approach
- Wisconsin Univ., Madison, WI (USA). Dept. of Nuclear Engineering and Engineering Physics Wisconsin Univ., Madison, WI (USA). Dept. of Physics
A combined fluid and kinetic description of magnetically confined plasmas is developed via a Chapman-Enskog-like procedure. This approach uses the density, energy, momentum, and heat flow conservation equations to recast the plasma kinetic equation with a full Fokker-Planck collision operator into an equation for F, the departure of the distribution function from a heat flow distorted dynamic'' Maxwellian. A density, momentum, and energy conserving Coulomb collision operator model is utilized in deriving the final form of the recast kinetic equation. The recast kinetic equation for the kinetic distortion F has been developed as follows. First, large flow velocities have been allowed for throughout the dynamics while an approximation has been used to simplify the Coulomb collision operator. Both the test particle and field particle parts of the Coulomb collision operator are retained and shown to cancel various frictional force and energy dissipation terms in appropriate limits. A drift kinetic limit of the dynamics and of the collisional effects is developed and shown to reproduce and extend previous derivations. Closure of the fluid moment equations through calculation of the anisotropic stress tensor {Pi} and anisotropic heat stress tensor {Theta} from the kinetic solution for F is discussed. As an application of this work, a more direct derivation of the flux-surface-averaged parallel viscous forces, which yield the neoclassical transport effects, has been developed by deductively applying the formalism developed in this thesis. Also, the poloidal variation of these viscous forces in the banana collisionality regime has been determined for the first time using this new formalism. Finally, preliminary studies of dynamical effects on the neoclassical viscous stresses are also discussed. 57 refs.
- Research Organization:
- Wisconsin Univ., Madison, WI (USA). Center for Plasma Theory and Computation
- Sponsoring Organization:
- DOE; USDOE, Washington, DC (USA)
- DOE Contract Number:
- FG02-86ER53218
- OSTI ID:
- 5906016
- Report Number(s):
- UW-CPTC-91-1; ON: DE91010969
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
700103* -- Fusion Energy-- Plasma Research-- Kinetics
BANANA REGIME
CHAPMAN-ENSKOG THEORY
COLLISIONS
CONFINEMENT
COULOMB FIELD
DIFFERENTIAL EQUATIONS
DISTRIBUTION FUNCTIONS
ELECTRIC FIELDS
EQUATIONS
FLUID FLOW
FOKKER-PLANCK EQUATION
FUNCTIONS
HEAT FLOW
KINETIC EQUATIONS
MAGNETIC CONFINEMENT
NEOCLASSICAL TRANSPORT THEORY
PARTIAL DIFFERENTIAL EQUATIONS
PLASMA CONFINEMENT
PLASMA DRIFT
TRANSPORT THEORY
TRAPPING
VISCOUS FLOW