Metal Agglomeration in Solid Propellants Combustion

Abstract

This article is a continuation of the work (Rashkovsky, 1998).The solution method of equation of metal agglomeration in solid propellants combustion theory is suggested. It is based on statistical tests method (Monte Carlo method). Different agglomeration mechanisms have been investigated and agglomerates probability density function for different ammonium perchlorate (AP) particles spectra have been obtained, as well as dependencies of average mass agglomerates diameter upon average mass diameter of AP particles. It is shown, that mass agglomerates distribution is of polymodal nature, which corresponds to known experimental data. Effect of different factors on agglomerates dispersity has been investigated. This paper includes analysis of different calculated schemes. Besides, the peculiarities of Monte Carlo method applying and common recommendations, necessary for making new calculation models of the metal agglomeration process in composite solid propellants combustion are considered. The effect of different process parameters on the agglomeration intensity are investigated.

Effect of acceleration on agglomeration of aluminum particles during combustion of composite solid propellants

“…If such a collision occurs, the larger the AP particle, the more probable agglomerate separation. This was called a collisional mechanism of agglomerate separation [9][10][11]. Simultaneously, another (aerodynamic) mechanism of separation is also involved, which is associated with the action of the mean flow of gases from the burning surface [9][10][11].…”

“…Agglomeration is calculated by the coupled mechanism by the Monte Carlo method [9][10][11] as follows.…”

“…Such a model was developed in [9][10][11] without using the pocket concept, which is believed to be a certain conventional notion and cannot be uniquely identified in a real propellant. The model [9][10][11] is statistical and allows one to calculate not only the mean-mass size of agglomerates but also the size distribution functions.…”

“…The effect of g-loads on agglomeration is studied in the present work within the framework of the statistical model developed in [9][10][11], and the size distribution functions of agglomerates are calculated for different values of the normal acceleration.…”

“…The model [9][10][11] is statistical and allows one to calculate not only the mean-mass size of agglomerates but also the size distribution functions. This model predicts experimentally observed correlations of the mean-mass sizes of separating agglomerates and oxidizer [ammonium perchlorate (AP)] particles [12,13].…”