硼与碳化硼单颗粒在高压空气中的燃烧特性OA

To elucidate the combustion mechanism of boron-based fuels under high-pressure conditions,the comparative study on the combustion characteristics of B and B4C particles was conducted in the air at 7 MPa using a self-developed laser-induced single-particle ignition and combustion experimental platform.The system integrates high-speed imaging,spectroscopic diag-nostics,and three-color pyrometry,enabling synchronous acquisition of key parameters,including flame morphology evolution,characteristic emission spectra,combustion temperature,and ignition delay time.The results show that B particles ignite rapid-ly and form a stable gas-phase diffusion flame,with an ignition delay time only 16％of that of B4C,accompanied by strong BO2 characteristic emission during combustion.In contrast,B4C exhibits significantly delayed ignition and predominantly sur-face-controlled combustion due to the high dissociation energy of B—C bonds and mass transfer limitations imposed by the car-bon-containing molten oxide layer,resulting in weak gas-phase radiation.Although the combustion temperature of B4C can reach approximately 80％of that of B,its overall reaction intensity remains lower.Under high-pressure conditions,enhanced oxygen diffusion promotes gas-phase chain reactions of boron,whereas the presence of carbon in B4C alters the reaction path-ways,transforming nitrogen from an inhibitor into a reactive participant.These findings provide experimental evidence and mechanistic insights for the efficient utilization of boron-based fuels in high-pressure propulsion systems.