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The effects of silane temperature and ambient moisture on the ignition behavior are considered. The critical velocity for delayed ignition is determined for different silane temperatures and moisture contents in ambient air. The logarithm of the critical exit velocity is found to be inversely proportional to silane temperature. It is also observed that moisture in air has a strong inhibiting effect on silane autoignition in air. From a safety perspective, it is concluded that prompt ignition of silane is favored in a high-temperature and low-humidity environment.

This paper describes an experimental setup and method for determining the combustion completeness of the gas and condensed phases of gasification products of energetic boron-containing condensed formulations in high-enthalpy subsonic air flow. The results of investigation of the combustion of a two-phase fuel mixture in a channel of constant cross section at various temperatures, pressures, and component ratios are given. The combustion regularities of a boron-containing condensed phase in a high-enthalpy air flow are identified. The obtained data can be useful in computational and experimental studies of operation processes in power plants.

A performance analysis and experimental study of a hybrid gas generator to be used in a ducted rocket are presented. Such a system exhibits potential advantages with regard to safety, performance, costs, availability of the fuel components, storability, and thrust control. A combination of a paraffin wax fuel and oxygen in the gas generator ensures a high regression rate and reveals oxidizer-to-fuel ratios as low as 0.14 in the gas generator (compared to the stoichiometric ratio of 3.4). A fuel regression rate correlation versus the oxidizer mass flux is derived, presenting a major advantage for the fuel flow rate management in comparison to control of the solid propellant gas generator burning rate through the pressure exponent, which requires mechanical interference with the hot nozzle flow to ensure a change in the combustor pressure and a corresponding change in the burning rate. Evaluation of the ducted rocket (with different oxidizers) versus pure ramjet performance shows a higher specific thrust for the former, though the latter exhibits a higher specific impulse.

A cylindrical shock wave in a dusty gas under the action of monochromatic radiation into the stellar atmosphere with a constant intensity per unit area is discussed. The gas is assumed to be grey and opaque, and the shock is assumed to be transparent. The dusty gas is considered as a mixture of a non-ideal gas and small solid particles. To obtain some essential features of shock propagation, small solid particles are considered as a pseudo-fluid, and it is assumed that the equilibrium flow condition is maintained in the entire flowfield. The effects of the parameters of the gas non-idealness, the mass concentration of solid particles in the mixture, the ratio of the density of solid particles to the initial density of the gas, and the radiation parameter on flow variables are investigated. It is shown that an increase in the gas non-idealness and the radiation parameter has a decaying effect on the shock waves, whereas the shock strength increases with an increase in the ratio of the density of solid particles to the initial density of the gas. It is found that an increase in the gas non-idealness and the ratio of the density of solid particles to the initial density of the gas has the opposite effects on the fluid velocity, pressure, and shock strength. It is also shown that an increase in the radiation parameter has a trend to decrease the flow variables and the shock strength.

This paper reports the synthesis, experimental and theoretical studies of a novel inorganic-organic cocrystal energetic material: methylamine triethylenediamine triperchlorate (MT). MT is synthesized by a rapid “one-pot” method. The performance test of MT shows that it is more powerful and has lower sensitivity in comparison to the benchmark energetic material, i.e., 2,4,6-trinitrotoluen (TNT). The molecular and crystal structures of MT are determined by means of x-ray diffraction (XRD). The compound crystallizes in a monoclinic system (space group Pn) with cell dimensions a = 8.975(18), b = 17.836(4), and c = 10.455(2) Å. The band structure and the density of states are calculated by an abbreviated form of the CASTEP code. The first principle tight-binding method within the general gradient approximation is used to study the electronic band structure, density of states, and Fermi energy. The results indicate that the main mechanism of cocrystallization originates from the Cl-O^…H hydrogen bonding between - ClO₄ and -NH₂.

This paper presents the results of numerical analysis of a viscoplastic model of the formation of hot spots based on the solid-phase mechanism of hot-spot ignition of an energetic porous material under shock-wave loading. The highly viscous pore collapse is considered, which is of great interest in the theoretical study of shock-wave initiation of heterogeneous energetic materials. Interphase heat transfer was described under the assumption that the gas is ideal and hence the uniform pressure condition can be used. Parametric analysis was conducted, and the specific features of the effect of heat transfer and interphase heat transfer on the critical conditions of shock-wave initiation of chemical reaction in the energetic porous material were determined.

Reactive materials are a new class of energetic materials that extremely and efficiently release energy under the influence of high impact loading. An impact tester is used in the present study to explore the impact ignition characteristics of Al/PTFE reactive materials and the impact ignition pressure of Al/PTFE reaction materials under different conditions. The experimental result shows that the critical ignition pressure is approximately 1.44 GPa. Meanwhile, it also shows that the material compactness has a much less pronounced effect on the impact ignition pressure for this reactive material if the loading time scales are of the order of several milliseconds. Plastic work and viscous heat both play a significant role in impact ignition. Finally, it is shown that impact ignition ensures a higher energy release rate than surface ignition.

The spectral-kinetic characteristics of luminescence of PETN with iron nanoparticle inclusions are measured in real time under laser initiation of an explosion (wavelength is 1064 nm, and pulse duration is 14 ns). During the action of the laser radiation pulse, the luminescence of the samples is observed, and explosive decomposition occurs in a microsecond time interval. The spectral pyrometry method is used to establish the thermal nature of explosive luminescence. The explosion temperature is estimated to be 3400±100 K.

The detonation velocities close to ideal velocity relative to large charges of highly dispersed ammonium perchlorate (APC) and its mixtures with different explosive substances in thick-walled steel pipes are measured. The relationship of the detonation velocity of APC with its density and the relationship between the detonation velocity of mixtures with the correlation of components and oxygen coefficient of the mixtures are determined. The calculation of the detonation velocity of APC/explosive/Al three-component compositions is proposed for the first time.

This paper describes the results of the experimental study on the effect of structural parameters, such as diameter, height, and density, on the development of explosive transformation of an NCP energy-intensive metal complex during bridge initiation. The results are compared with those obtained in shock-wave initiation.