Pocket model of aluminum agglomeration with a tetrahedral cell for composite propellants

A tetrahedral structure model has been proposed to estimate the size of metal agglomerates during combustion of a composite solid propellant. According to this model, oxidizing particles are located at the vertices of a regular tetrahedron, and the internal volume of the pyramid is occupied by a mixture of binder fuel and metal – the so-called pocket. Experimental data are compared with the results of calculations using the tetrahedral model, the Cohen model and the empirical correlations of Hermsen, Salita, Beckstead, Grigoriev, and Duterque. The comparison was carried out for a composite propellants containing ammonium perchlorate, binder and aluminum as an example. It has been shown that in some cases the tetrahedral model predicts the diameter of agglomerates better than the other models.