Accession Number : AD0661586

Title :   NONUNIFORM ELECTRICAL CONDUCTION IN MAGNETOHYDRODYNAMIC CHANNELS.

Descriptive Note : Interim rept.,

Corporate Author : STANFORD UNIV CALIF INST FOR PLASMA RESEARCH

Personal Author(s) : Oliver,David A.

Report Date : MAY 1967

Pagination or Media Count : 182

Abstract : Methods of describing steady electrical conduction in a partially ionized gas with Hall effect, strong applied or magnetically induced electric fields, and a nonuniform electrical conductivity are proposed. One of these methods is based on model conductivity distributions, and the other is based on a nonequilibrium conductivity and incorporates the electron energy and ionization equations. The occurrence of a nonequilibrium conductivity leads to the development of an ionization instability. It is shown that the steady equations with a nonequilibrium conductivity are of mixed elliptic-hyperbolic type and that the condition for the uniform ellipticity of these equations is identical to the condition for the prevention of the ionization instability. These methods are applied to flowing gases in two-dimensional linear magnetohydrodynamic channels with segmented electrode structures. Detailed numerical solutions for current and potential are obtained. In general, it is found that conductivity nonuniformities lead to a degradation of performance as reflected in increased internal impedance of the conducting gas and depressed Hall voltage. Theoretically obtained distributions of current on electrodes in contact with a nonuniformly conducting gas are found to be in accord with experimental measurements. (Author)

Descriptors :   (*MAGNETOHYDRODYNAMICS, *ELECTRICAL CONDUCTIVITY), GAS IONIZATION, HALL EFFECT, ELECTRIC FIELDS, STABILITY, TWO DIMENSIONAL FLOW, ELECTRODES, NUMERICAL ANALYSIS

Subject Categories : Electricity and Magnetism
      Plasma Physics and Magnetohydrodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE