1. on the combustion characteristics of HAN. In general, three areas of research have been conducted: (1) determination of combustion behavior and flame structures [4-9], (2) identification and quantification of species formed during thermal decomposition [10-14], and (3) development of analytical approaches for predicting the burn rate [15-16].
2. To model combustion of HAN-based propellants, a fundamental understanding is needed of the physical and chemical processes that occur during thermally induced decomposition of HAN. However, it is very difficult to characterize the condensed-phase reactions, because optical access is not possible due to the dynamic behavior that occur during bubble formation at high heating rates. To simulate actual combustion phenomena, a high heating rate must be achieved. However, it has been possible to heat the sample only at rates up to 200600K/sec in other experimental facilities [17-18]. The technique employed in this study yields heating rates exceeding 1500K/sec in order to study the decomposition behavior under isothermal conditions. Thus, kinetic information can be deduced from the acquired data, and it ispossible to improve the predictive capability of combustion models.
3. EXPERIMENTALSETUP Confined Rapid Thermolysis (CRT)/FTIR Device The overall setup consists of a test rig and a Nicolet 740 FTIR spectrometer with its accompanying optics. Detailed description ofthis system, as shown in Fig. 1, is available [20]. This test rig is composed of three parts: 1) test chamber, 2) upper and lower heater components, and 3)temperaturemeasurement system. The height and inner diameter of the chamber, as shown inFig.2, are 23.8 cmand 12.4 cm,respectively. Visual observation of the sample holder is possible through two quartz windows. ZnSe windows are used to allow transmission of the modulated beam of the FTIR. Two, high-watt density cartridge type heaters (Omega CIR-1014/120), are each embedded within a copper rod of 12.5 mm diameter and 45 mm length. These heater blocks are initially located within a fiber glass insulation material outside the chamber to prevent pre-heating of the sample. The upper heater probe is lowered manually, and the bottom heater portion is raised by a pneumatic piston (Schrader Bellows)throughtheguidingtubes.
4. Gases Band Comments 860-980 NH3