Aluminum agglomerate size measurements in composite propellant combustion

Experimental and numerical investigation have been done to evaluate the aluminum agglomerate size in AP/HTPB/Aluminum propellants and compared it with burning rate results. Bimodal AP particle size distribution is considered in the present work. The effect of aluminum size, aluminum content, fine AP size, fine AP/binder ratio and coarse AP size in aluminum ignition, accumulation and agglomerate formation during combustion, typically in their ranges, are focused. The burning rates were found to be higher for the propellants with lower fine AP/binder ratio. The agglomerate sizes for the propellants with 10% Al was found to be higher than those with 15 and 18% aluminum. Observing the agglomerate sizes and the burning rate trends, it can be concluded that the agglomerate sizes vary inversely as the burning rates.