Experimental study of agglomerate size distribution of aluminized propellants using digital inline holography

Large molten agglomerated particles are formed with the combustion of aluminized ammonium perchlorate composite propellants, which may result in poor combustion performance, slag accumulation, and increase two-phase flow losses. Quantifying the 3-D information of agglomerate particles distributions are needed to gain an understanding of agglomeration dynamics and ultimately design new propellants to improve performance. In this work, the results of combustion under 0.1MPa show that this technique is able to capture the particles which from about 30?m to 700?m. Based on the propellant combustion surface, the particle size distribution of aluminum agglomerated particles in the four height spaces from the burning surface was obtained, and Granularity statistics was obtained. With the height increases, the particle size distribution of the aluminum agglomerated particles shifts to smaller size, and the distribution of the small particle size gradually increases.