Ignition and combustion of aluminum particles in H2/O2/N2 combustion products

The ignition and combustion of aluminum particles is studied at high pressures and temperature in the combustion products of nitrogen-diluted premixed H-2/O-2 mixtures in a high-pressure, constant-volume combustion chamber. A novel approach is used to inject particles after sufficient delay for gas-phase combustion transients to equilibrate, permitting the particles to ignite and burn at high ambient temperature and nearly constant pressure conditions. Particle ignition and combustion are monitored optically by measuring combusting particle emissions. The methodology is used to measure the ignition and combustion times of similar to 22-mu m spherodized aluminum particles over a range of pressures (38-145 atm), at 2630 K, and in 20% excess oxygen concentration. Measured ignition delays and combustion times are compared to independent data showing very good agreement.