SOME MEASUREMENTS OF ROTATIONAL TEMPERATURES IN A LOW DENSITY WIND TUNNEL USING ELECTRON BEAM FLUORESCENCE.
Abstract
The fluorescence of a 30 kV electron beam has been used as a probe to measure the rotational distribution function of flowing nitrogen in a low density wind tunnel. The fluorescence consists predominantly of the so-called first negative system of nitrogen. Measurements of the intensities of the rotational structure of the (0-0) vibrational band have been used to calculate, through a theoretical model, the original rotational distribution function of N2 before excitation. A series of measurements was performed in the undisturbed flows of subsonic nozzle, a Mach 4 noizle, and free jet expansions from sonic orifices at Mach numbers ranging up to 19. The rotational temperature measurements are shown to be about 3% high at 280 K, with a progressively increasing error at lower temperatures. These measurements also indicated no measurable lag in rotational temperature in the free jet expansion. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1965
- Accession Number
- AD0466305
Entities
People
- F. Robben
- L. Talbot
Organizations
- University of California, Berkeley