The dissociation rate coefficient for oxygen in argon, , was measured using laser absorption near 216 nm in the Schumann–Runge system in a shock tube. A mixture of 2% oxygen in argon was studied behind reflected shocks at initial equilibrium temperatures from 4400 to 7900 K and pressures from 0.2 to 1 atm. The dissociation was modeled decoupled from vibrational relaxation because dissociation was evident only after the test gas mixture was near vibrational equilibrium. The dissociation rate coefficient was determined by fitting the measured oxygen absorbance time history for each experiment using temperatures based on the incident shock speed and the shock relations and adjusting the A-factor of the dissociation rate coefficient. Good agreement was found with the prior experimental work and model of Camac and Vaughan. Consistent results were also obtained for measurements with constant pressure as well as increasing pressure, validating our method to account for pressure changes by including the pressure profile in the dissociation model.
Measurements of Oxygen Dissociation Using Laser Absorption
Journal of Thermophysics and Heat Transfer ; 30 , 2 ; 274-278
2016-02-16
5 pages
Article (Journal)
Electronic Resource
English
DIODE LASER ABSORPTION SPECTROSCOPY MEASUREMENTS IN A GASEOUS HYDROGEN / OXYGEN ROCKET
British Library Conference Proceedings | 2011
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