THE MAGNETIC STABILIZATION OF AN ELECTRIC ARC IN TRANSVERSE SUPERSONIC FLOW.
MICHIGAN UNIV ANN ARBOR
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A method is presented for the magnetic confinement and stabilization of a d-c electric arc in an unheated supersonic airstream directed normal to the electric field. It is shown that stable confinement is governed by dynamic processes in the positive column, and is independent of material and flow conditions at the surface of the cathode. The positive column exhibited remarkable spatial stability when allowed to slant across the electric field, parallel to a freestream Mach line. Under conditions where the column could not follow the Mach angle, a very unstable discharge was observed. The direction of column slanting was the Hall direction, cathode-root downstream but the magnitude of the slant angle was not affected by changes in the Hall parameter, corresponding to changes in ambient pressure, arc current, and local magnetic induction by factors of 2. At the Mach numbers investigated, 2.0 and 2.5, the stable column invariably followed the Mach angle -- which happens to be very nearly the angle corresponding to a maximum in the discharge parameter, the ratio of parallel component of electric field to pressure at the upstream boundary of the arc. The experimental results demonstrate the possibility of stable conduction of electricity through transverse supersonic flow, and suggest that such conduction is governed by a convective interaction mechanism which is not entirely Hall-effect. A general review of the convective arc is given, and results of the present investigation are compared with those of previos investigations. Author
- Electricity and Magnetism
- Plasma Physics and Magnetohydrodynamics
- Electric and Ion Propulsion