Accession Number:

ADA409137

Title:

Reaction Kinetics of O(3P) and OH With Diamine Rocket Fuels

Descriptive Note:

Technical paper rept.

Corporate Author:

AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE WEST

Personal Author(s):

Report Date:

1998-07-08

Pagination or Media Count:

13.0

Abstract:

The gas phase kinetics of Osup 3P and OH reactions with the three diamine fuels N2H4, CH3NHNH2 and CH32NNH2 has been studied in a discharge flow-tube apparatus. The reactions were studied in 2 torr of He under pseudo-first-order conditions in the transient species concentration with a known excess of diamine concentration. The steady-state concentration temporal profiles of the transient species were directly monitored by fluorescence techniques to deduce the absolute second-order reaction rate coefficients. The Arrhenius expressions 7.35 - 2.16 x 10exp -13 e640 - 60T, 2.71 - 0.04 x 10exp -11 e-190 - 50T and 1.96 - 0.29 x 10exp -11 e20 - 40T cu cmmolecs in the temperature range 252-640 K were obtained for reactions of Osup 3P with N2H4, CH3NHNH2 and CH32NNH2, respectively. The corresponding expressions 1.25 - 0.19 x 10 exp -11 e315 - 55T, 2.88 - 0.04 x 10exp -11 e210 - 55T and 2.00 - 0.30 x 10exp -11 e330 - 80T cu cmmolecs in the range 232-374 K were determined for the OH reactions. Our recent measurement of the total yield of OHXsup 2II formation in the O - N2H4 reaction of 0.15 - 0.05 at 298 K of which 50 was found to be produced hot with vibrational excitation up to the limit of reaction exothermicity and the present observed experimental kinetic trends suggest that the initial addition of Osup 3P and OH to the hydrazine molecule followed by rapid dissociation to products is an important process. Alkylation in the diamine molecule also allows direct H-abstraction mechanism to operate in these reaction systems.

Subject Categories:

  • Atomic and Molecular Physics and Spectroscopy
  • Rocket Propellants

Distribution Statement:

APPROVED FOR PUBLIC RELEASE