EXPERIMENTS ON JOULE HEATING OF SHOCK-IONIZED AIR WITH PARTICULAR EMPHASIS ON THE BOUNDARY LAYERS OF THE ELECTRODES IN THE DISCHARGE CHAMBER.
Abstract
By means of selective heating of the electron gas, the conductivity of a gas can be made to exceed its equilibrium value at the same gas temperature. The method of Joule heating of the gas by a D. C. discharge was employed. All experiments were carried out with air in a 3 1/2 inch diameter shock tube. The gas behind the reflected shock develops an important thermal and viscous boundary layer at the walls of the electrodes, comprising the discharge chamber. The primary purpose of the experiments was to determine their effect on Joule heating of the air. The current density in the discharge chamber ranged from 300 to 7,000 A/sq cm. Due to the boundary layers, a current density in excess of 600-700 A/sq cm is required to efficiently heat the gas. Non-equilibrium conductivity measurements were made and compared with those computed theoretically. The distribution of voltage and current density between the electrodes was investigated. By photographing the current discharge, its stability and uniformity was determined. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1966
- Accession Number
- AD0645636
Entities
People
- S. Selamoglu
Organizations
- Brown University