Published 6 issues per year
ISSN Print: 2150-766X
ISSN Online: 2150-7678
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DETERMINATION OF TEMPERATURE AND OH CONCENTRATION PROFILES OF RDX/CAB PSEUDO PROPELLANTS USING UV/VISIBLE ABSORPTION SPECTROSCOPY
ABSTRACT
In this paper, burning rates, temperature and OH concentration profiles of pure RDX and pseudo propellants containing RDX with CAB binder having 8, 11, and 14 percent by weight were determined. UV/Visible absorption spectroscopy was used as the diagnostic technique to determine the gas-phase temperature and OH species concentration profiles. The deduced final flame temperatures from absorption measurements are 3062 K for pure RDX, 2990 K for RDX/CAB (92/8%), 2806 K for RDX/CAB (89/11%), and 2742 K for RDX/CAB (86/14%) at 0.45 MPa. In order to examine the pressure dependency of final flame temperatures and OH mole fractions, absorption measurements were also conducted at 0.17 and 0.79 MPa for pure RDX. The results showed that pure RDX has a final flame temperature of around 2950 K at 0.17 MPa and 3220 K at 0.79 MPa. The deduced final flame temperatures are in good agreement with equilibrium calculations. The deduced OH concentrations from absorption measurements are lower than equilibrium calculations due to the non-one-dimensionality of the flame causing uncertainties in the effective pathlength of the light beam. During the tests, it was observed that there was no multistage flame structure for both pure RDX and pseudo propellants with RDX/CAB mixtures. Thermocouple measurements for pure RDX indicated that the surface temperature is about 600 K at 0.17 MPa and 675 K at 0.79 MPa.