Characteristics of the Flow of an Ionized Perfect Gas Through a Magnetic Field

Abstract

The problem of the compressible flow of a perfect gas with constant fractional ionization through a magnetic field is considered. The Joulean heat dissipation is assumed to be taken out of the gas so that the flow can be treated as isentropic. The present analysis differs slightly from others previously reported in the literature [1, 2, 3, 4] mainly in that the entire conductivity tensor and the variation of its elements with gas properties are taken into account. It is felt that the somewhat unrealistic condition of isentropic flow is much less restrictive than the assumption of a scalar constant conductivity. Under these conditions, a relatively simple integration of the flow equations is possible. The assumption of isentropic flow implies that the difference in stagnation enthalpies at the entrance and exit of the magnetic field region is equal to the electrical output plus the Joulean heat. Therefore the ratio of the output power to the difference in stagnation enthalpies gives a measure of the Joulean heat dissipation and hence of the efficiency of the device.