Structure and initiation of plane detonation waves in a bidisperse gas suspension of aluminum particles

Abstract

Initiation and propagation of plane waves of heterogeneous detonation in a stoichiometric suspension of two fractions of aluminum particles in oxygen are analyzed numerically. It is found that the detonation is not ideal, and the steady-state part of the shock-wave structure is bounded by an equilibrium frozen sonic point. Initiation criteria depend on the particle-size distribution of the mixture. Initiation by explosive shock waves can lead to formation of unstable two-front structures. Addition of a small amount of fine particles into the discrete phase allows the initiation energy to be substantially reduced.

Formation and degeneration of cellular detonation in bidisperse gas suspensions of aluminum particles

“…Detonation in bidisperse suspensions was studied in [9,10]. Based on an analysis of a self-similar solution of nonideal detonation, the possibility of existence of two-front regimes in a bidisperse suspension of monofuel particles was demonstrated in [9].…”

“…Based on an analysis of a self-similar solution of nonideal detonation, the possibility of existence of two-front regimes in a bidisperse suspension of monofuel particles was demonstrated in [9]. The processes of initiation and propagation of plane detonation waves in a bidisperse gas suspension of aluminum particles in oxygen were numerically examined in [10]. Significant differences from monodisperse suspensions were observed, in terms of both the initiation scenario and the structure of steady-state waves.…”

Physical and mathematical model of detonation in aluminum gas suspensions with regard for transition processes of nanosized particle flow, heat transfer and combustion

“…Fedorov et al [6,[10][11][12][13][14]19]. This criterion was substantiated in [27] when considering the ignition of aluminum particles in a shock wave, taking into account surface oxidation reactions and polymorphic transformations of the oxide.…”

“…According to the data given in [16], the burning time of aluminum particles in a mixture of oxygen and nitrogen in the range 10 nm -100 nm obeys the dependence [6] used in the analysis and numerical modeling of micron particle suspensions [10][11][12][13][14]19], the reaction of reduced kinetics was assumed to be of the Arrhenius type with an activation energy of 32 kJ/mol (half the data for aluminum nanoparticles), thus reflecting the transitional combustion regime.…”

“…Strauss [7] on propagation velocity and detonation pressure. The problems of detonation initiation and propagation in monodisperse and polydisperse mixtures and specific features of cellular detonations were investigated in [8][9][10][11] for aluminum suspensions with particle diameter from 1 μm to 10 μm. Studies of plane and cellular detonation diffraction on backward step were performed in [12][13][14][15].…”