Numerical Simulation of Formation of Cellular Heterogeneous Detonation of Aluminum Particles in Oxygen

Abstract

Formation of cellular detonation in a stoichiometric mixture of aluminum particles in oxygen is studied by means of numerical simulation of shock-wave initiation of detonation in a flat and rather wide channel. By varying the channel width, the characteristic size of the cells of regular uniform structures for particle fractions of 1-10 µm is determined. The calculated cell size is in agreement with the estimates obtained by methods of an acoustic analysis. A relation is established between the cell size and the length of the characteristic zones of the detonation-wave structure (ignition delay, combustion, velocity and thermal relaxation).

Effects of different product phases in aluminum dust detonation modeling

“…In fact, the variation in chemical reaction coefficients has the same mechanism as the change in heat release, because both change the heat release before the CJ plane. Fedorov and Khmel [31] used variable heat release to make sure the detonation velocity remains the same as the experimental result for different particle concentrations. Benkiewicz and Hayashi [13] introduced the endothermic reaction…”

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].…”

Analysis of the influence of inert particles on the propagation of a cellular heterogeneous detonation

“…The formation of cellular detonation of monodisperse mixtures of fine aluminum particles and oxygen was modeled as a consequence of the development of small disturbances on the planar detonation front, which were caused by a small local inhomogeneity of particle density. The part of the solution including undisturbed flow, the leading shock wave and the detonation structure with a part of the adjacent rarefaction wave is posed as initial conditions in the calculations [16]. The channel length and the initial position of the detonation wave were chosen so that the flow velocity in the rarefaction wave at the left boundary was directed outwards (opposite to the main detonation flow).…”