SOME ASPECTS OF SECONDARY ATOMIZATION OF ALUMINUM HYDROCARBON SLURRY PROPELLANTS

A theoretical and experimental investigation of the secondary atomizat ion of Al/RP-1 slurry propellants was conducted. Theoretical efforts e xamined the effects of aluminum particle size in particle shell/crust formation on the surface of a burning slurry droplet. A model was deve loped for the pressure buildup and mechanical stresses in the shell fo r the time period after the shell becomes impermeable. Experimental ef forts focused on the ignition and combustion of a dilute stream of slu rry droplets. Measurements of individual particle diameters and veloci ties were made at various axial locations in the stream. Radiant emiss ion from the particles was also monitored to determine whether aluminu m was actively burning. Experimental aluminum agglomerate ignition tim es were found to be comparable to theoretical estimates. The experimen tally measured minimum initial slurry droplet diameter for secondary a tomization was 20-25 mum, compared to a theoretical diameter of 35 mum .