Accession Number : ADA189940

Title :   MPD (Magnetoplasmadynamic) Thrust Chamber Flow Dynamics.

Descriptive Note : Annual rept. 1 Oct 86-30 Sep 87.

Corporate Author : R AND D ASSOCIATES ALEXANDRIA VA

PDF Url : ADA189940

Report Date : 29 Sep 1987

Pagination or Media Count : 60

Abstract : Performance characteristics of Magnetoplasmadynamic(MPD) arcjets depend on proper matching of electromagnetic and fluid mechanical constraints within the thrust chamber. Experimental measurements of internal flow conditions during MPD arcjet operation are needed to guide developement of flow models and to assess the validity of theoretical predictions. Efforts are continuing in a corporative effort to apply an array of diagnostic techniques including time-, space-, and spectrally-resolved photography to examine MPD arcjet internal flows. Experimental elucidation of the internal flow structure is used to develop predictive models for optimal geometries and operating parameters. Probes have been used to map the current and voltage distributions within uniform height and flared annular channels. This work is concerned with the effect of thruster channel variations on the current conduction regions of the MPD internal flow. Other aspects of the internal flow structure that have been modeled involve the transition of the input mass flow from neutral gas to electrically-conducting plasma. Scale sizes for the transition region were estimated in terms of the electrical and thermodynamic properties of the propellant gas (e.g., argon). These estimates indicate that the electrical conductivity of the flow can be established in distances that are small compared to the characteristic dimension for current conduction near the entrance to the arcjet thrust chamber.

Descriptors :   *MAGNETOHYDRODYNAMICS, *ARC JET ENGINES, *PLASMA ENGINES, ARGON, CHANNELS, DIAGNOSIS(GENERAL), DISTRIBUTION, DYNAMICS, ELECTRIC CONDUCTORS, ELECTRICAL PROPERTIES, EXPERIMENTAL DATA, FLOW, INPUT, INTERNAL, MEASUREMENT, METHODOLOGY, MODELS, OPTIMIZATION, PLASMAS(PHYSICS), PREDICTIONS, PROPELLANTS, SCALE, SIZES(DIMENSIONS), THEORY, THERMODYNAMIC PROPERTIES, THRUST CHAMBERS, VALIDATION, VOLTAGE, ELECTRICAL CONDUCTIVITY

Subject Categories : Electric and Ion Propulsion

Distribution Statement : APPROVED FOR PUBLIC RELEASE