Accession Number:

AD0294131

Title:

EXPERIMENTAL MEASUREMENTS OF TEMPERATURE AND RELAXATION TIMES BEHIND SHOCK WAVES

Descriptive Note:

Corporate Author:

ADVISORY GROUP FOR AERONAUTICAL RESEARCH AND DEVELOPMENT PARIS (FRANCE)

Personal Author(s):

Report Date:

1959-09-01

Pagination or Media Count:

24.0

Abstract:

By using a photomultiplier and cathode-ray oscillograph responsive only to changes in light signal, the sodium-line reversal technique has been adapted for time-resolved studies of temperature behind shock waves produced by a bursting diaphragm. A double-beam system has also been developed, which eliminates changes due to varying concentration of added metal, and interference filters can be used instead of a spectrograph. General agreement between calculated and observed temperatures is obtained, but both air and oxygen show a high-temperature region due to burning at the interface with the hydrogen driver gas. In nitrogen around 2400 K, a low temperature region close to the shock front may be attributed to a vibrational energy lag of the order of 100 microseconds, the sodium excitation following the effective vibrational temperature rather than the translational temperature of the nitrogen. In oxygen, evidence for a dissociation relaxation effect is obtained for shocks, giving temperatures of around 2500 K this produces an abnormally high temperature near the front.

Subject Categories:

  • Combustion and Ignition

Distribution Statement:

APPROVED FOR PUBLIC RELEASE