Accession Number:

AD0471389

Title:

EXPANSION OF A PARTIALLY-IONIZED GAS THROUGH A SUPERSONIC NOZZLE

Descriptive Note:

Technical rept.

Corporate Author:

CALIFORNIA UNIV BERKELEY INST OF ENGINEERING RESEARCH

Personal Author(s):

Report Date:

1965-08-01

Pagination or Media Count:

54.0

Abstract:

A theoretical investigation was made of the non-equilibrium expansion of a partially ionized gas through a supersonic nozzle. Both hydrogen and argon were studied. The ionization and recombination rate parameters used were those calculated by Bates and co-workers, using their collisional-radiative model of the recombination process. These calculations, for hydrogen, include the influence of radiation trapping on the over-all rates, and yield as well the amount of recombination energy which is gained by the third-body electron in the recombination. The energy balance for the electrons and massive particles was studied for both the optically thin all recombination radiation lost and optically thick all radiation absorbed cases. It was found that the recombination process produces an increase in electron temperature over that of the ion-atom temperature, and that this temperature difference is greater for the optically thick than for the optically thin case. Also, there is more net recombination for the optically thin case. For high initial ionization 62, recombination affects the gross flow variables measurably, when compared with the frozen flow solution. For low initial ionization 1 the gross flow variables are practically unaltered, and the principal effect of the recombination is to produce an elevated electron temperature. On comparing the hydrogen and argon flows, one finds that the effect of the larger atomic mass of the argon is to diminish the effectiveness of electron-atom energy exchange, resulting in a larger difference between electron and atom temperatures.

Subject Categories:

  • Physical Chemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE