Propulsion and Combustion Lab 222
RESEARCH PROPOSAL ABSTRACT
Combustion of Boron based Pyrotechnic Compounds
שריפת תערובות פירוטכניות על בסיס בורון
Boron based gelled fuels are promising candidates for certain future ramjet applications, offering potential improvements in performance and/or safety over conventional liquid and solid systems. Before such fuel can be developed, however, a fundamental understanding of combustion of the gel droplet is required and several problems of ignition and agglomeration of boron particles have to be solved. This study addresses the combustion behavior of micro-pyrotechnic clusters of boron suspended in kerosene based gel fuels. The pyrotechnic clusters are supposed to ignite in a “dry window” between the end of the kerosene evaporation and the liquefaction of the boron oxide. Operation in this time frame will allow the pyrotechnic reaction to heat up and disperse the boron particles, solving some of the problems that prevented the use of boron as an efficient fuel. The research combines both experimental and theoretical investigations of the gel combustion. In the experimental part, pyrotechnic clusters with different oxidizers will be tested in order to understand the ignition phenomena in the system. In addition to the combustion tests of gel droplets, calorimetric tests of the pyrotechnic mixture will be conducted. The theoretical part aims to determine the temperature and pressure profiles inside the burning gel droplet. This will allow determining the existence of temperature gradients inside the droplet that may offer a “dry window” during the droplet combustion. The existence of a pressure gradient over the droplet outer layer may explain various phenomena such as secondary atomization that can break the droplet into smaller parts and improve combustion efficiency.