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This paper presents the experimental study of ignition and combustion of micro- and nanoparticles of aluminum diboride as part of pyrotechnic energy-saturated compositions in a gas generator with an air afterburner chamber and the thermodynamic calculations of combustion of pyrotechnic compositions based on aluminum diboride in air. The discharge of the combustion products from the afterburner chamber is recorded on video. It is shown that replacing micron aluminum diboride by powdered diboride with a mass-average diameter of particles equal to ≈270 nm in the pyrotechnic composition and increasing the pressure in the afterburner chamber cause the combustion efficiency in air to increase by 5–20%.

This paper presents the results of a numerical and experimental study of gasification of carbonaceous materials in the filtration combustion mode using mixtures of air with CO₂ as an oxidizer. The results obtained are compared with the results on gasification of carbonaceous materials by a steam-air mixture. It is shown that the replacement of steam in the gaseous oxidizer by an equal volume CO₂ leads to a marked reduction in the combustion temperature. The maximum calorific values of the product gas in coal gasification by a mixture of air and CO₂ are close to the values obtained for steam-air gasification.

Experiments aimed at studying the ignition of coal dust obtained by coal disintegration in high-energy mills are performed in a tubular furnace. Effective kinetic constants of ignition of coal dust ground in a vibrational-centrifugal mill and in a disintegration mill under conditions of rapid heating are determined for the first time. It is shown that the volatile release rate depends on the method of coal grinding.

This paper presents the results of an experimental determination of the width of the reaction zone in a detonation wave in nitromethane sensitized by diethylenetriamine. It was found that increasing the mass concentration of diethylenetriamine from 0 to 2.0% reduced the typical reaction time by a factor of less than two while the critical diameter decreased by an order of magnitude. This discrepancy is explained by the fact that the critical detonation diameter of neat nitromethane is determined not by the reaction time but by flow instability at the edge of the charge, manifested in the occurrence of a wave of reaction disruption. Increasing the initial rate of nitromethane decomposition by addition of diethylenetriamine leads to flow stabilization and thus to a change in the nature of the critical diameter.

To better understand the detonation characteristics of ammonium nitrate (AN) and activated additives mixtures, potassium chloride (KCl) and monoammonium phosphate (MAP) are mixed with AN by different mixing methods. The UN gap test and scanning electron microscopy are applied to study AN and AN-additive mixtures. For the mechanical mixing method, the detonation velocity of AN-additives decreases with increasing the additive proportion, while the detonation velocity of modified AN prepared by the solution mixing method shows the opposite tendency. It is proved that the sensitivity to shock waves increases as the size of AN particles decreases. The type of additives, the mixing methods, and the particle size distribution are important parameters that affect the detonation characteristics of AN.

An underwater explosion test is used to determine the detonation properties of metallized explosives containing aluminum and boron powders. An oxygen bomb calorimeter (PARR 6200 calorimeter, Parr Instrument Company, USA) is used to obtain the heat of combustion of the metal mixtures. As the content of boron powders is increased, the heat of combustion of the metal mixtures increases, and the combustion efficiency of boron decreases. The highest value of the combustion heat is 38.2181 MJ/kg, with the boron content of 40%. All metallized explosive compositions (RDX/Al/B/AP) have higher detonation energy (including higher shock wave energy and bubble energy) in water than the TNT charge. The highest total useful energy is 6.821 MJ/kg, with the boron content of 10%. It is 3.4% higher than the total energy of the RDX/Al/AP composition, and it is 2.1 times higher than the TNT equivalent.

The optical thermal radiation arising from the shock collapse of glass or polymer microballoons in a transparent condensed medium (water or polymerized epoxy resin) was detected. The temporal characteristics of the detected radiation in the pressure range 0.5–29 GPa at different viscosities of the material surrounding the pore were determined. The brightness temperature of hot spots was estimated to be 1600–3200 K at a pressure of 2–29 GPa. The length of the leading edge of the radiation pulse corresponding to the time of hot-spot formation increases from 2·10^–8 to 30·10^–8 s, depending on the shock-wave intensity and the viscosity of the material surrounding the pore. Analysis of the data shows that in the pressure range 5–29 GPa, hot-spot formation is dominated by the hydrodynamic mechanism of collapse and in the range 0.5–5 GPa, by the viscoplastic mechanism.

A pure emulsion based on an aqueous solution of ammonium nitrate placed in a steel tube 114 mm in inner diameter was shock loaded. The achieved dynamic pressure of 30 GPa, far exceeding the calculated detonation pressure, did not lead to the development of an explosive process.

The analysis of the dynamic response of a circular tunnel in three types of soil at different depths under surface detonation of a 250-kg TNT charge reveals that the tunnel peak particle velocity and the failure zone length are sensitive to the soil type and material properties. The buried tunnel in silty clay sand has the least damage; the length of the failure zone is 5 m in the longitudinal direction and 0 to 60^oC at the top arch.

Regimes of continuous spin detonation of two-phase kerosene-air mixtures with small addition of hydrogen are obtained for the first time in a flow-type annular cylindrical combustor 503 mm in diameter.