- Author
- Macek, A. | Semple, J. M.
- Title
- Composition and Combustion Characteristics of Condensed Exhaust From Boron-Containing Fuel-Rich Rocket Motors.
- Coporate
- Atlantic Research Corp., Alexandria, VA
- Report
- AFOSR-TR-72-2379, October 1972, 9 p.
- Distribution
- Available from National Technical Information Service
- Keywords
- combustion | solid propellants | boron | ignition
- Identifiers
- fuel-rich propellants; air-breathing propulsion; particle combustion
- Abstract
- The objective of this work has been to characterize the nature of the primary exhaust from fuel-rich boron-containing (ca. 50%) rocket motors, and to study its combustion. Two formulations were studied, each at two pressures. Solid materials collected from motor firings were examined microscopically, analyzed chemically, and studied for ignition temperatures and burning times, tb. Both the theory and the experiment show that boron undergoes substantial chemical reaction in primary combustion. Both soluble and insoluble boron compounds form (B2O3, A12 MgO4, B4C and others). The minimum gas temperatures for ignition of the exhaust material are the same as those for pure boron: 1980 deg K for fine particles (-10 um) and 1850 deg K for 30-40 um particles. Burning times of the exhaust material are also roughly the same as for pure boron. Even through our measurement of tb is rough, it appears that for small particles tb is not proportional to d2, but to a power of diameter closer to unity.