Specific Features of Detonations in Polydisperse Suspensions of Micro- and Nanosized Reactive Particles

摘要

The processes of detonation propagation in polydisperse suspensions of aluminum particles in a wide range of sizes (from several micrometers to 300 nm) have been studied by numerical simulation of two-dimensional flows. The conditions for the occurrence and development of transverse waves of cellular detonation and the attenuation and suppression of detonation are analyzed. The model takes into account that the burning characteristics (in particular, the activation energy of the reduced kinetics) change with decreasing particle size according to the transition from the diffusion mode of combustion to the kinetic one. The aim of the study is to determine the effect of the fractional composition on the detonation characteristics of aluminum suspensions. It has been established that the degeneracy properties of cellular detonation, characterized by a significant attenuation of transverse waves in a bi-dispersed suspension of micro-sized aluminum particles, are retained when the fraction of nano-sized aluminum is added to the mixture. With the predominance of the nano-dispersed fraction in the mixture, on the contrary, the transverse wave degeneration does not occur, and cellular detonation is characterized by high values of peak pressures at triple points.