The combustion of aluminized composite solid propellants is always accompanied by accumulation of oxidized aluminum particles on the reacting surface. Accurate measurement and prediction of agglomerate sizes have a significant influence on estimating two-phase flow loss of solid rocket motors, as well as calculating the infrared radiation and others. A dynamic particle size test system, which is mostly responsible for real-time particle size detection, was applied to measure agglomerate sizes during the burning of AP/HTPB compound propellants in solid rocket motor under 6 MPa. At the working stage of solid rocket motor, the Malvern Spraytec Analyzer was applied to analyze the size of agglomerate at 60 cm from nozzle outlet. Three recipes, which are no catalyst, CF (containing fluoride) contained and PF (poly fluoride) contained, for reducing the size of agglomerate were considered in this paper. Three replicates were performed under each formulation, and the results are highly reproducible. In repeated experiments of the same propellant, no significant change was detected from the measured size during the stable combustion in solid rocket motor. The presence of CF and PF leads to a decrease in the mean agglomerate sizes. Moreover, catalyst CF has a better influence on reducing the agglomerate sizes than PF. Compared with the results of literature, the test results are consistent with Hermsen and Liu model and the test system proved to be valid.
agglomeration, aluminized propellants, size distribution, combustion