EXPERIMENTAL EVALUATION OF FLUSH ELECTROSTATIC PROBES FOR REENTRY MEASUREMENTS
Abstract
The current collection characteristics of flush-mounted electrostatic probes were determined in a simulated reentry boundary layer flow. The thermochemistry and fluid dynamic profiles on sharp cones at 180 to 100 kft altitude are simulated by a subsonic flow of arc-heated air in a 1/2 x 2 in. cooled channel. The experimentally determined probe currents are correlated with the known channel electron densities using two theoretical models developed by Chung and Bredfeldt et al. It is found that for electron densities of order 10 to the 10th power to 10 to the 13th power Chung's theory correlates the data well. High temperature materials were tested, and stainless steel electrodes in pyrolytic boron nitride insulators are recommended for operation up to surface temperatures of 1400 deg K. Comparison of the two theoretical models in predicting flight performance shows them in excellent agreement for sodium-contaminated ablating cones below 175 kft. For the low electron densities on sharp cones in clean air, neither theory is valid above 115 kft altitude. Detailed graphs and tables of flight environment, materials properties, and probe electrical characteristics are presented.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1967
- Accession Number
- AD0660531
Entities
People
- W. P. Thompson
Organizations
- The Aerospace Corporation