The research progress on the aluminum agglomeration in solid propellants was reviewed. The limitations of present studies was discussed

followed by the analysis of valuable research directions of agglomeration models in future. The physical process of aluminum agglomeration can be divided into three stages

accumulation

aggregation and agglomeration. The present agglomeration models may be classified to five categories

which are empirical model

pocket model

physical model

random packing model and condensed-layer model

respectively. Highly accurate and widely applicable models used to predict the aluminum agglomeration behavior is still lacking. Developing new agglomeration models which can predict the size distribution of the agglomerates with low computational expense will be a hot issue in future. Physical model is promising due to its capability of the description of agglomeration nature. The combustion experiments of aluminized propellants was conducted at pressure of 5MPa

and agglomerate diameters on the propellants burning surface were obtained by a high-speed camera coupled with a microscope. The experimental results were compared with the prediction results of Hermsen model and Salita model. The prediction errors of agglomeration diameter are 8.7% and 9.6% by Salita model

for propellants with burning rate of 5.1mm/s and 8.0mm/s

respectively

whereas the prediction error reachs 19.2% by Hermsen model for the high burning rate propellant. Overall

it is shown that Salita model has a more reasonable accuracy.