Cyclotetramethylene tetranitramine/glycidyl azide polymer/butanetriol trinitrate propellant flame structure

The nonintrusive techniques of planar laser-induced fluorescence, ultraviolet/visible absorption spectroscopy, and spontaneous laser Raman spectroscopy were used to map out species and temperature profiles above the surface of self-deflagating cyclotetramethylene tetranitramine (HMX)/glycidyl azide polymer (GAP)/butanetriol trinitrate (BTTN) model propellant with a pseudo premixed flame. CO, H2O, NO2, and H2CO were found to be the major species at the surface, NO, CO, H2O, and HCN in the dark zone, and CO, H-2, H2O, and CO2 in the burnt gases. A dark zone of about 1400-1450 K was observed in which the NO and HCN concentrations were at their highest, about 15.5 and 13.5 mol%, respectively. NO2 peaked close to the surface at about 5 mol%. Formaldehyde and N2O were also observed in the gas phase, peaking at the surface at about 7 and 8 mol%, respectively. Thermal diffusivity and specific heat capacity as a function of temperature were also measured. Analysis of thermocouple measurements showed a surface temperature of 785 K. Comparisons are made between this propellant and the previously investigated cyclotetramethylene trinitramine (RDX) analog. (C) 2004 The Combustion Institute. Published by Elsevier Inc. All rights reserved.